Microbial Science: Career Paths, Demands for Skills, and International Trends in Employment and Publications
Donna K. Ginther1,2
Patricia Oslund3
Carlos E. Zambrana4 June 28, 2024
1Donna K. Ginther is the Roy A. Roberts & Regents distinguished professor of economics at the University of Kansas, director of the Institute for Policy and Social Research at the University of Kansas, and member of the National Bureau of Economic Statistics.
2The authors thank Stefano Bertuzzi and Janet Hedrick for productive conversations and interest in this work. This report, its findings, and any errors are the sole responsibility of the authors and do not represent any official position of the National Science Foundation, Lightcast, or the University of Kansas. This report was prepared for the American Society for Microbiology (ASM) to support efforts at understanding the microbial sciences workforce today. The ASM requested that the University of Kansas Institute for Policy and Social Research conduct a study of skills and the international reach of microbial science.
3Patricia Oslund is an associate research scientist in the Institute for Policy and Social Research at the University of Kansas.
4Carlos E. Zambrana Roman is an associate research scientist in the Institute for Policy and Social Research at the University of Kansas.
Foreword
It is my pleasure, on behalf of the American Society for Microbiology, to introduce Microbial Science: Career Paths, Demands for Skills, and International Trends in Employment and Publications.
Building on the foundation of our first workforce report, Workforce Trends: The Future of Microbial Sciences, this new installment provides essential insights into the evolving landscape of microbial sciences. This comes at a time when our field is at a critical juncture for meeting the challenges and opportunities of the future, with ASM embracing its responsibility to provide the community with the most updated and reliable information about the status of the microbiology workforce. It is our hope that this will help trainees and their mentors, together with all established professionals navigate their career path.
This report reveals key trends that are reshaping the profession. In the past two decades, we have witnessed a profound shift in career paths for those with microbiology doctorates, with an increasing share of the profession being employed by industry and a decreasing share working in tenure-track academic positions. This data underscores the growing need for educators and institutions to adapt their curricula to meet the demands of a global, industry-driven workforce.
At ASM, we recognize that the microbial sciences are undergoing a rapid transformation, and it is our responsibility to support our members in navigating these changes. This report serves as a vital resource for understanding how the profession is shifting and how we can prepare for the future. Educators, in particular, will find these insights invaluable as they adjust their teaching methods and curricula to better align with the reality that many microbiology careers now lie outside of academia and within industry settings. This shift calls for a reimagining of educational pathways, ensuring that the next generation of microbial scientists is equipped with the skills needed to thrive in diverse professional environments.
Also illustrated in this report is the expanding global footprint of our field. As the scientific community becomes more connected and integrated across the globe, it is more important than ever that we work together to build a workforce that is adaptable, innovative, and prepared for the challenges and opportunities ahead. The data presented in this report, along with insights from our previous study, will be instrumental in guiding our efforts to develop an engaged and forward-thinking workforce.
We are grateful for the continued partnership with Dr. Donna Ginther, one of the top labor economists specializing in the study of the scientific workforce. ASM commissioned this report from Dr. Ginther, and I would like to thank her for her collaboration in shaping this resource for our microbial science community. Dr. Ginther, as the Roy A. Roberts & Regents Distinguished Professor of Economics at the University of Kansas, Director of the Institute for Policy and Social Research, and a member of the National Bureau of Economic Research, brings extensive experience in the field of STEM labor economics to this work.
I hope that the insights in this report allow our members, partners and the entire microbial sciences community to gain a deeper understanding of our workforce. With the comprehensive picture this report provides—highlighting both our field’s strengths and areas for growth—I am confident it will empower us to further strengthen the field of microbial sciences. Together, we can build a more resilient and dynamic future for our profession.
Stefano Bertuzzi, Ph.D., MPH Chief Executive Officer, ASM
Executive Summary
This is a continuation of the Institute for Policy & Social Research (IPSR) work with the American Society for Microbiology. In this report, we focus on the career paths of microbiologists, the demand for scientific skills and the international breadth of microbial science. Microbiologists work across various occupations, and it can be challenging to identify the workforce in federal statistical data. This report examines a variety of surveys and administrative data to track trends in the microbial science workforce. We compare microbiology to the related lab-based fields of chemistry and biochemistry/biophysics combined. The report identifies the share of microbiologyrelated job openings over time to quantify demand for microbiologists today. Highlights from this report include:
• Between 2001–2021, the number of microbiology doctorates is lower than in chemistry and biochemistry/biophysics but has been growing more rapidly than both of those fields.
• Between 35–45% of microbiology doctorates were working in industry during 2001–2021. The share working in tenure-stream academic positions fell from 22% to 16% in 2021. Government employment increased from 7% in 2001 to 12% by 2021.
• Between 2001–2021, trends in the employment sector for chemistry doctorates have remained flat, with a slight decrease in industry employment.
• Industry employment in biochemistry/ biophysics increased from 35% in 2001 to more than 40% by 2021. Employment in academia fell, especially for non-tenure-stream employees.
• Between 2001–2015, academia was the largest employment sector for early career microbiologists and biochemists/biophysicists. Starting in 2017, industry became the predominant employment sector, most likely reflecting a decline in the share of early career scientists taking a postdoc. In mid- and late-career, industry was observed to be the leading employment sector for microbiology,
chemistry and biochemistry/biophysics doctorates.
• Microbiology doctorates are more likely to change jobs and employers than chemistry and biochemistry/biophysics doctorates. Primary reasons for changing jobs include pay, working conditions and job location.
• The number of microbiology degree holders with a bachelor’s or master’s degree is growing more slowly than that of degree holders with chemistry or biochemistry/biophysics degrees. Industry is the largest employment sector for these majors between 2001 and 2021.
• Job postings for microbiologists in clinical and managerial settings have decreased since 2023, stabilizing at pre-pandemic levels. Between 2020–2023, there were an average of 2,000 job postings per year for microbiology jobs requiring a doctorate. There were about 1,000 microbiology doctorates awarded in 2022.
• Microbiologists are less likely to work in the pharmaceutical preparation manufacturing industry compared to 10 years ago. Microbiologists in a clinical setting are more likely to work for employment agencies, and microbiologists in a managerial setting are more likely to work in hospitals.
• Demands for specific skills have remained relatively stable during the past 5 years.
• International microbiology doctorates increased from 25% to 29% between 2015–2021. The share of international students in microbiology is significantly lower over the 2000s than that in chemistry and biochemistry/biophysics, which awards over 40% of doctorates to international students.
• Students from Asia received 18% of all microbiology doctorates between 2017–2021. The share of students from Asia receiving doctorates in chemistry (35%) and biochemistry/biophysics (31%) was much larger.
• Microbiology doctorates trained in the U.S. were significantly more likely to work in academia if they
lived abroad (68%), compared to other fields and compared to microbiology doctorates working in the U.S. (43%).
• Half of U.S.-trained microbiology and chemistry doctorates working abroad were employed in Asia. However, only 2.5% of microbiologists employed abroad were in China, compared to 11% of chemistry doctorates. One quarter of U.S. trained microbiology, chemistry and biochemistry/ biophysics doctorates were employed in Europe.
• Microbiology publications have tripled in the past 2 decades. Chemistry publications have nearly tripled.
• In the past 20 years, researchers from China have published more papers in all 3 fields than any other country.
• Biochemistry publications have fallen in the past decade in all countries except for China.
• The U.S. has the highest country H-index in microbiology, chemistry and biochemistry. The U.S. microbiology H-index is 3 times the size of China’s. This indicates that U.S. research continues to have a greater impact on science.
• Researchers based in China are 50% more likely to cite other researchers in China in microbiology, chemistry and biochemistry. Rates of U.S. researchers citing other researchers based in the U.S. have trended downwards in the past decade. The microbial sciences workforce continues to evolve after the COVID-19 pandemic. As the American Society of Microbiology considers the future of the doctoraltrained microbiology workforce, they should keep 2 related trends in mind. The share of microbiologists working in tenure or tenure-track academic jobs dropped considerably from 22% in 2001 to 16% in 2021. At the same time, China surpassed the U.S. in microbiology publications. Unless more research jobs are created in the future, the U.S. advantage in research impact may also become jeopardized.
Introduction
This report examines the career progression of microbiologists, tracks job changes among doctorates in microbiology and updates the analysis of the demand for microbiologists, along with the skills being demanded. It also examines the employment of U.S.trained microbiology doctorates abroad, as well as international trends in microbiology publications. It uses data from multiple sources to show these trends and compares microbiologists to the related fields of chemistry and biochemistry/biophysics.
Information on the career paths of microbiologists is drawn from the National Survey of College Graduates (NSCG) and the Survey of Doctorate Recipients (SDR). The SDR is also used to study job changes and U.S.-trained doctorates working abroad. The Survey of Earned Doctorates (SED) examines trends in international doctorate production in these fields.
Information on the demand for microbiologists and job openings by occupation and industry are derived
from the Lightcast labor market analytics. Lightcast scrapes job listings, posts and related sources from the internet, collecting tens of thousands of jobs postings from across the U.S., and provides detailed data from job listings about occupation name and type, required skills, salary range (when available) and other job characteristics. These data give the most accurate sense of the broad U.S. labor market and the demand for jobs from the employer side.
We compiled data on publication trends from the Scimago Journal & Country Rank website.5 ScimagoJR bases their journal and country rankings on data from Scopus. Country rankings are based on authors located in each country. ScimagoJR counts the number of publications in a given scientific field by year and country. Citations to those documents and self-citations within a country are also provided. The country’s H-index is the number of publications from that country between 1996-2023 with at least that same number of citations (Hirsh 2005).
5Access to Scimago is available at: https://www.scimagojr.com/index.php.
Analysis
Career Dynamics of Doctorates
This report compiles relevant data on microbiologists and compares them to those in other, similar fields: biochemists/biophysicists and chemists. We begin with an analysis of career progression. In this part of the report, we focus mostly on individuals with a doctorate in microbiology because the data are of higher quality. Figure 1 shows the number of microbiology doctorates by SDR survey year from 2001–2021 and the number employed. The total number of microbiology doctorates grew by about 5,000 in the past 20 years, roughly 63%. The share of employed microbiologists increased by a similar amount. Figure 2 shows the same analysis for chemistry. During the same period, chemistry was a much larger field than microbiology—there were about 4.44 times as many chemists as microbiologists in the U.S. Growth in chemistry was much slower than in microbiology over the past 20 years. From 2001-2021, approximately 10,000 chemists were not working.
Figure 1: Total Number of Microbiology Doctorates from U.S. Institutions Living in the U.S. by Year
Source: Survey of Doctorate Recipients (SDR)
Figure 2: Total Number of Chemistry Doctorates from U.S. Institutions Living in the U.S. by Year
Source: Survey of Doctorate Recipients (SDR)
Source: Survey of Doctorate Recipients (SDR)
Figure 3 reports this analysis for biochemistry and biophysics combined. From 2001-2021, the combined fields were somewhat larger than microbiology, and they also experienced slower growth of about 35%. Like microbiology, about 5,000 biochemistry and biophysics doctorates were not working during this period.
We examined the employment sector of doctorates in microbiology, chemistry and biochemistry and biophysics combined in the past 2 decades. We focused on the employment sector because industry is not measured in the SDR or the NSCG. Figure 4 shows the employment sector of microbiology doctorates from 2001-2021. Industry was the predominant and growing sector, increasing from 35% to close to 40% of all employed microbiologists. If academic tenure-track and non-tenure-track positions were combined, it would be the largest sector in 2001, but second largest in 2021. Academic tenure-track employment fell from 22% in 2001 to about 17% in 2021. Academic non-tenure-track employment, including postdoctoral researchers, non-tenure-track faculty and research scientists, peaked in 2013 but subsequently fell to similar levels of tenure-track employment. Government employment grew to about 12% by 2021.
Source: Survey of Doctorate Recipients (SDR)
Figure 3: Total Number of Biochemistry and Biophysics Doctorates from U.S. Institutions Living in the U.S. by Year
Figure 4: Percentage of Microbiology Doctorates by Employment Sector and Year
Source: Survey of Doctorate Recipients (SDR)
Figure 5 shows the same analysis for chemistry doctorates. From 2001-2021, about half of chemistry doctorates worked in industry. This changed little over 20 years. Close to 30% of chemistry doctorates worked in academia, equally split between tenure-track and non-tenure-track. A higher share, close to 20%, were either unemployed or out of the labor force. Biochemistry and biophysics employment patterns showed a marked increase in industry employment, which increased from 36% in 2001 to 42% by 2021 (Figure 6). Like microbiologists, academic employment of chemists dropped over the decades, especially in the tenure-track sector from 22% in 2001 to 16% in 2021.
Source: Survey of Doctorate Recipients (SDR)
Figure 5: Percentage of Chemistry Doctorates by Employment Sector and Year
Figure 6: Percentage of Biochemistry and Biophysics Doctorates by Employment Sector and Year
Doctorate careers are dynamic. Most microbiologists, chemists, biochemists and biophysicists begin their careers as postdoctoral researchers (postdocs) and are employed in the academic sector. After the postdoc, these scientists may remain in academia in tenure-track or non-tenure-track positions or may find work in another sector, such as industry or government. To examine these career paths, we categorized scientists into early career (0–10 years since Ph.D.), mid-career (11–20 years since Ph.D.) and late career (21 years or more since Ph.D.) and examined their career sector for each year of the SDR from 2001-2021. Figure 7 shows that about 40% of microbiologists started their careers in non-tenure-track academia, most likely postdoctoral positions. This was true until 2017 when the share dropped, reaching 30% by 2021. Most of those early-career microbiologists switched to industry, which increased from 30% to close to 45% by 2021. A mere 10% of early-career microbiologists were working in tenure-track academic positions by 2021. By 11-20 years since their Ph.D., many of the former postdocs had transitioned into industry. Roughly 40% were in industry, 40% were in academia, equally split between tenure and non-tenure-track, and the rest were in government or not working. For older workers, 30% were out of the labor force, while the shares in industry and academia also fell.
Source: Survey of Doctorate Recipients (SDR)
Figure 8 performed the same analysis for chemistry doctorates. In 2001, 60% of early-career doctorates were working in industry. That share dropped to 50% by 2013 and then rebounded to 60% by 2021. A similar share of mid-career chemistry doctorates were working in industry in the 2000s, but that number dropped to just over 50% by 2021. Employment in industry was the primary sector for late-career chemists as well, but it dropped to about 40% as those scientists retired. Interestingly, the share of chemists in tenure-track academia was roughly constant across career stages, fluctuating between 10-20%. Employment in non-tenure-track academia fluctuated around 20% during the early career, and then dropped as the career stage progressed. Overall, the career paths of chemists were stable across years and career stage.
Figure 7: Percentage of Microbiology Doctorates by Employment Sector, Career Stage, and Year
Source: Survey of Doctorate Recipients (SDR)
In contrast, biochemist and biophysics doctorates showed varied career paths across years and career stages (Figure 9). Like microbiologists, roughly 40% of early-career scientists were employed in non-tenure-track academia (most likely the postdoc). Starting around 2013, these postdoc positions dropped, and industry positions increased. During mid-career, the share employed in tenure-track academic positions dropped by 10%. The share working in industry increased dramatically as did the share working in non-tenure-track academia. During the senior career stage, employment shifted downward, but industry employment continued to be the predominant sector.
Source: Survey of Doctorate Recipients (SDR)
Figure 8: Percentage of Chemistry Doctorates by Employment Sector, Career Stage, and Year
Figure 9: Percentage of Biochemistry and Biophysics Doctorates by Employment Sector, Career Stage, and Year
Next, in Table 1, we examine changes in jobs for doctoral scientists. From 2001-2021, microbiologists were more likely to change employers than biochemists/biophysicists or chemists. In 2021, 75% of microbiologists had the same employer and same job, compared with 78% of biochemists/biophysicists and chemists. Microbiologists were more likely to have a different employer but the same job (10%), compared to biochemists/biophysics (9%) and chemists (7%). These are considered lateral job changes. Microbiologists were also more likely than other scientists to have different employers and different jobs.
1: Total Number and Percentage of Job and Employer Changes by Field
Source: 2021 Survey of Doctorate Recipients (SDR)
Figure 10 reports the reason that microbiologists changed jobs, where people could select multiple reasons. Pay, working conditions and job location were the 3 leading reasons for changing jobs. Over 60% reported pay as the reason for finding new employment.
10: Percentage of Microbiology Doctorates who Changed Jobs by Reported Reason, 2019-2021
Source: 2021 Survey of Doctorate Recipients (SDR)
Career Dynamics of Bachelors’ and Master’s Degree Recipients
Using the National Survey of College Graduates, we performed a similar employment sector analysis for individuals with undergraduate or master’s degrees in microbiology. Unfortunately, the sample sizes were very small, making the data too noisy to conduct the career path analysis. Figure 11 shows the employment results for microbiologists, chemists and biochemists/biophysicists. From 1999-2021, the number of biochemistry and biophysics degree holders combined was roughly the same size as those with microbiology degrees, but the number of graduates grew more quickly. The number of chemistry degree holders grew the most rapidly, but about 100,000 chemistry majors were not in the labor force or were unemployed.
Table
Figure
In Figure 12, we examined the employment sector for microbiologists, biophysicists/biochemists and chemists from 1999-2021. In all 3 fields, over half of graduates were employed in industry. Between 20-30% of graduates were not in the labor force or were unemployed. The share of employment in academia was flat in microbiology and chemistry but increased in biochemistry and biophysics. The share of employment in government trended down for all groups over time.
Figure 11: Percentage of Microbiology Bachelor’s and Master’s Degrees by Employment Sector, Career Stage, and Year
Source: National Survey of College Graduates (NSCG)
Figure 12: Percentage of Chemistry Bachelor’s and Master’s Degree by Employment Sector, Career Stage, and Year
Source: National Survey of College Graduates (NSCG)
Taken together, the career-stage analysis underscores the increasing importance of industry employment at the doctoral level in microbiology, biochemistry and biophysics. Given the flat NIH budget in the 2023 fiscal year and the low pay of postdocs (NIH 2023), it is unlikely that these trends will reverse anytime soon. Our analysis also indicated that doctorates in microbiology are more likely to change jobs than in other fields, primarily because of pay. Bachelor’s and master’s degree recipients in all 3 fields were shown to work predominantly in industry throughout their entire careers. We next turned our attention to labor demand for microbiologists.
Labor Demand
Employers post positions that require microbiology training. We used Lightcast data to create 3 definitions of microbiologists using standard occupation codes (SOCs), following the approach we developed in Heggeness, Zambrana and Ginther (2023). First, we queried Lightcast for those job postings that used Microbiology as a specialized skill.6 We classified those occupations into microbiologists using only the SOC 19-1022 code and broader definitions of individuals working as microbiologists in clinical and managerial settings. Table 2 reports the occupations that we used to define clinical and managerial microbiologists.
19-1042
11-9111
11-3051
11-9121
19-1029
29-2018
19-4099
15-2031
19-1022
Source: Lightcast
Medical Scientists, Except Epidemiologists
Medical and Health Services Managers
Industrial Production Managers
Natural Sciences Managers
Biological Scientists, All Other Clinical Setting
Clinical Laboratory Technologists and Technicians
Life, Physical, and Social Science Technicians, All Other
Operations Research Analysts
Microbiologists
We also provided updates on our previous analysis of job postings and advertised wage rates. Figure 13 shows job postings for microbiologists in clinical settings, microbiologists in managerial settings and the microbiologist occupation code (19-1022). Job postings for clinical microbiologists peaked in 2022, likely in response to the pandemic. Since that time, job postings for clinical microbiologists have stabilized at pre-pandemic levels. Job postings for microbiologist managers remained steady through late 2023 but have trended downward for the past 2 quarters. Job postings for microbiologists (19-1022), narrowly defined, have been flat.
6Microbiology specialized skills include any job ads that include the following terms: microbiology, diagnostic microbiology, microbiological testing, medical microbiology, pathogenic microbiology, food microbiology, agricultural microbiology, microbiological culture, molecular microbiology, pharmaceutical microbiology, soil microbiology, and the certifications of technologist in microbiology (M-ASCP), specialist in microbiology (SM-ASCP), and American Board of Medical Microbiology (ABMM).
Table 2: Standard Occupation Codes for Clinical and Managerial Microbiologists
Figure 13: Total Number of Job Postings for Occupations with Microbiology as a Specialized Skill, 2019-2024
Source: Lightcast (2023)
Figure 14: Job Postings for Occupations with Microbiology as a Specialized Skill and Minimum Degree Requirement of a Doctorate, 2020–2024.
Source: Lightcast (2024)
In Figure 14, we also examined unique job postings for microbiologists with a minimum of a doctorate degree. We eliminated postdoctoral positions from the analysis. To anchor these data, in 2022 there were 1,089 microbiology and immunology doctorate degrees awarded in the U.S. The number of unique job postings was twice that number. Job posting data are larger than actual hires, so these numbers should be interpreted with caution. Nevertheless, as of 2024, the number of jobs posted exceeds the number of doctorates being produced.
Just over one-third of job postings list advertised salaries. Salaries have generally been increasing. Between May 2021-April 2024, advertised salaries for microbiologists in clinical settings have seen a 16% increase (Figure 15). The advertised wages for microbiologist positions in managerial settings have grown similarly with an overall increase of 17%. Salaries among the narrow microbiologist (19-1022) classification have grown at the same rate as microbiologists in clinical settings.
It is likely that the increased demand for microbiologist positions has caused at least some of the increase in advertised salaries. Other reasons could include churn in the workforce, shifts in the skillsets required to perform work in posted positions or geographic changes in advertised positions toward higher cost-of-living areas. These increases in salary within microbiology are not surprising, given the overall trend in national wage and salary increases across industry and sector since the start of the pandemic.
$67,840
$57,216
$53,888 $62,336
Source: Lightcast
We also examined salaries by years of experience and type of microbiology job (Table 3). Starting salaries for inexperienced clinical microbiologists averaged close to $60,000. One third of the 9,705 job advertisements listed salaries. Advertisements for clinical microbiologists with 7-10 years of experience had an average listed salary of $87,300. Managerial salaries for less experienced microbiologists averaged $80,000. Those with 10 or more years of experience listed salaries at $123,000. There were very few advertisements for experienced microbiologists requiring a doctorate. The advertisements for new doctorates listed starting salaries at $98,000.
Figure 15: Advertised Salary Trends for Jobs with Microbiology as a Specialized Skill, 2021-2024
Table 3: Advertised Salaries for Jobs with Microbiology as a Specialized Skill by Years of Experience, 2023–2024.
Source: Lightcast
In addition to salaries, we examined the industries hiring clinical and managerial microbiologists in 2014 and 2024. While the industries have not changed much in the past decade, the share of jobs in each industry has shifted. Table 4 shows that job advertisements from hospitals have dropped by 4%, while jobs from employment placement agencies have increased by 7%. Jobs for microbiologists in pharmaceutical preparation manufacturing have also dropped by 3% over the past decade.
Table 4: Advertised Industry for Jobs with Microbiology as a Specialized Skill in a Clinical Setting, 2014 and 2024.
Source: Lightcast
We conducted a similar analysis for microbiologists in a managerial setting (Table 5). As with clinical microbiologists, job advertisements for managerial microbiologists in pharmaceutical preparation manufacturing have dropped by 7% over the past decade. In contrast, jobs in hospitals and physician offices have each increased by 5%.
Table 5: Advertised Industry for Jobs with Microbiology as a Specialized Skill in a Managerial Setting, 2014 and 2024.
Source: Lightcast
Lightcast keeps track of the skills mentioned in advertisements, and we tracked those skills over the past 5 years (2019–2024). These skills could be as general as Microsoft Office or Good Lab Practices (GLP), or as specialized as a scientific procedure. As an illustration, we have included a graphic produced by Lightcast that shows the flow of the top 20 skills mentioned in job ads for microbiologists in a clinical setting over a 5-year period (Figure 16). The depth of the skill (i.e., whether it is toward the top or bottom of the figure) shows its prevalence in the ads, and the order shows how the skill has changed in relative importance over time. By definition, “microbiology” is the most prevalent skill in this occupation. “Quality control” is consistently listed as important, while “immunology” has decreased in relative importance over the ensuing 5 years. American Medical Technologists (AMT) Certification was unimportant during the COVID-19 pandemic but has become a more frequent skill mentioned in the past year. Overall, the specific skills demanded have been relatively stable.
For each definition of microbiology occupation, Lightcast also reports the top 100 fastest growing skills. We narrowed the list to the scientific topics that experienced the largest growth. Table A1 in the appendix presents these results. While the number of job ads that featured these skills is small relative to the number of job postings, the large percentage change in these skills could be indicative of the growing importance of these skills and certifications.
Figure 16: Top 20 Skills in Job Advertisements for Microbiologists in a Clinical Setting, 2018–2024.
Source: Lightcast
Our results show that demand for microbiologists remains robust coming out of the COVID-19 pandemic. Advertised salaries have increased over the past 5 years by about 16% but have remained flat in the past year. Demand for microbiologists in the pharmaceutical preparation manufacturing industry has dropped considerably, but it has been replaced by an increase in demand in employment placement agencies for clinical microbiologists, as well as for managerial microbiologists in hospitals and physician offices. Future work with skills mentioned in job advertisements could be used to inform educators about the growing skill needs of students and their future employers.
Trends in Microbiology, Chemistry and Biochemistry and Biophysics Doctorates
Awarded to Individuals Born Outside of the U.S.
For decades, the share of doctorates awarded in STEM disciplines to individuals born outside of the U.S. has increased (National Science Board, 2022). Using the Survey of Earned Doctorates and the Survey of Doctorate Recipients, we can track the share of degrees awarded to international students and U.S.-trained students working abroad. Figure 17 reports the share of doctorate degrees awarded to international students in microbiology, chemistry and biochemistry and biophysics from 2015-2021. Chemistry and biochemistry/biophysics awarded just over 40% of degrees to international students. In contrast, the share of international students who received microbiology doctorates at U.S. institutions was much lower but growing. In 2015, 25% of microbiology degrees were conferred to international students and, by 2021, that share had risen to 29%.
Figure 17: Microbiology, Chemistry and Biochemistry/Biophysics Doctorates Awarded to International Students, 2015–2021.
Source: Survey of Earned Doctorates
International students come from many parts of the world. Using the Survey of Earned Doctorates, Figure 18 shows the region of origin of these students. Between 2017 and 2021, about 4% of doctoral degrees from U.S. institutions were awarded to students from Europe in all 3 fields. Asian students made up the largest share of international students receiving degrees; however, the share of Asian students was much lower in microbiology (18%) compared to 30% in biochemistry/biophysics and 34% in chemistry.
Figure 18: Microbiology, Chemistry and Biochemistry/Biophysics Doctorates Awarded to Individuals Born Outside of the U.S. by Birth Region of the World, 2017–2021.
Source: Survey of Earned Doctorates
Using the Survey of Doctorate Recipients, we examined the sector of employment for U.S. doctorates working outside and inside the country from 2017–2021. Close to 70% of microbiologists working abroad were employed in academia and just over 30% work in non-academic jobs. The share was much lower for chemists and biochemists/ biophysicists, with 55% working in academia and 44% in non-academic employment (Figure 19). Figure 20 shows the share of U.S. doctorates employed in academic and non-academic jobs in the U.S. during this same period. Forty-three percent of microbiology and biochemistry/biophysics doctorates were employed in academia. A much lower 35% of chemists were employed in that sector. Higher shares of microbiology, chemistry and biochemistry/ biophysics doctorates were employed in the non-academic sector in the U.S.
Figure 19: Microbiology, Chemistry and Biochemistry/Biophysics Doctorates from U.S. Institutions Working Outside of the U.S. by Sector, 2017–2021.
Source: Survey of Doctorate Recipients (SDR)
Figure 20: Microbiology, Chemistry and Biochemistry/Biophysics Doctorates from U.S. Institutions Working Inside of the U.S. by Sector, 2017–2021.
Source: Survey of Doctorate Recipients (SDR)
In addition to employment sectors, we identified the region, and, in some cases, the country, where these students were employed. Figure 21 shows that close to one quarter of U.S. trained doctorates in microbiology, chemistry and biochemistry/biophysics were employed in Europe. That is notable given that only 4% of U.S.-trained doctorates are born in Europe (Figure 18). China sends about 35% of international STEM students to the U.S. (National Science Board, 2022). However, from 2017-2021, only 2.5% of U.S.-trained microbiologists working abroad were employed in China. This was much lower than the 11% of chemistry and 13% of biochemistry/biophysics doctorates employed in China. Half of microbiology and chemistry doctorates were working in other Asian countries besides China. Another 12% of doctorates from all 3 fields were working in the Americas, but outside of the U.S. Although only 3% of U.S.-trained microbiologists were working in Africa, over 7% were employed in Oceania. Table 6 provides additional detail on countries that employed U.S.-trained microbiology, chemistry and biochemistry/biophysics doctorates from 2017-2021. Germany and the United Kingdom employed between 4% to 6% of doctorates in these 3 fields. Larger shares of U.S.-trained microbiologists were working in South Korea (12%) and Taiwan (14%) than in China. South Korea employed a larger share of chemistry and biochemistry/biophysics doctorates than China.
Figure 21: Microbiology, Chemistry and Biochemistry/Biophysics Doctorates from U.S. Institutions Working Abroad by Region, 2017–2021.
Source: Survey of Doctorate Recipients (SDR)
Table 6: Microbiology, Chemistry and Biochemistry/Biophysics Doctorates from U.S. Institutions Working Abroad by Region and Country, 2017–2021.
Source: Survey of Doctorate Recipients (SDR)
In terms of international students and those working abroad, microbiology differs considerably from chemistry and biochemistry/biophysics. Microbiology trains fewer international students overall compared to other fields. Less than 20% of microbiology doctorates come from Asia. In contrast, 35% of chemistry doctorates and 31% of biochemistry/
biophysics doctorates are awarded to students from Asia. When U.S.-trained microbiology doctorates are employed abroad, they are more likely than their U.S.-employed counterparts to be working in academia than in the other fields. Over half of microbiologists employed abroad are working in Asia, but only 2.5% are employed in China.
Next, we examine international patterns of research productivity.
International Trends in Publications and Research Impact
We used data compiled by the Scimago Journal and Country Rank website (ScimagoJR 2024). ScimagoJR has synthesized Scopus data into journal and country rankings for over 300 scientific categories. This allowed us to examine publication and research impact trends by country in microbiology, chemistry and biochemistry.7 Publications are categorized by the field of the journal and the countries of the authors. If a paper had coauthors from both the U.S. and Canada, the paper is counted as a publication in each of the 2 countries. To the extent that papers have international collaborations, this means that these papers are double counted in country rankings. ScimagoJR also calculates a country’s H-index (Hirsch 2005)—the number of papers published by authors in the country between 1996 and 2023 with at least the same number of citations. Finally, we can track the country’s self-citations. These are the number of papers authored in a country that cite other papers from that country.
Figure 22 shows publications in microbiology journals from 2003–2023 for the top 10 countries8 and the rest of the world. The total number of microbiology publications almost tripled from 17,000 publications in 2003 to 50,000 papers by 2023. In 2003, the top 10 countries published two-thirds of all papers, but, by 2023, those countries only published just over half of microbiology papers. Figure 23 shows the publication trends for the top 5 countries. Publication growth in the U.S. increased from 4,000 to 6,000 papers per year. There was also slow growth in publications in Germany, the United Kingdom and France. The surprising growth in publications came from China. By 2011, China published more microbiology papers than the European countries. By 2021, China’s publications surpassed the U.S. Since 2022, China has published 4,000 more microbiology papers per year than the U.S.
Figure 22: Microbiology Publications in the Top 10 Countries and Rest of the World, 2003–2023.
Source: ScimagoJR
7The analysis of publication trends in biochemistry excludes publications in biophysics.
8The top 10 countries in microbiology publications from 1996–2023 are in order: U.S., China, Germany, United Kingdom, France, Japan, Spain, India and South Korea.
Figure 23: Microbiology Publications in the Top 5 Countries, 2003–2023.
Source: ScimagoJR
We performed the same analysis for chemistry. Figure 24 shows that chemistry publications almost tripled between 2003 and 2023, increasing from 150,000 to 442,000. The top 10 countries9 produced two-thirds of all chemistry papers during these past 2 decades. Figure 25 shows the publication trends for the top 5 countries. The number of chemistry publications in China and India was 10 times and 5 times greater in 2023 compared to 2003, respectively. Chemistry publications in the past 2 decades grew by 45% in Germany and 35% in the U.S. but fell by 11% in Japan. Starting in 2009, China published more chemistry papers than the U.S.
Figure 24: Chemistry Publications in the Top 10 Countries and the Rest of the World, 2003–2023.
Source: ScimagoJR
9The top 10 countries in chemistry publications from 1996–2023 are in order: U.S., China, Japan, Germany, India, United Kingdom, France, Russian Federation, South Korea and Spain.
Figure 25: Chemistry Publications in the Top 5 Countries, 2003–2023.
Source: ScimagoJR
Figure 26: Biochemistry Publications in the Top 10 Countries and the Rest of the World, 2003–2023.
Source: ScimagoJR
27: Biochemistry Publications in the Top 5 Countries, 2003–2023.
Source: ScimagoJR
Publication trends in biochemistry are significantly different compared with microbiology and chemistry. Biochemistry publications increased by 85% in the past 2 decades (Figure 26). Growth was rather flat through 2017 but accelerated sharply after that. The top 10 countries10 published 72% of papers in 2003, but that share fell to 62% by 2023. Figure 27 shows the publication trends in the top 5 countries. Publication numbers fell in all countries except for China, where biochemistry publications increased 11-fold. Biochemistry publications fell by over 25% in the U.S. and by 37% in Japan. Biochemistry publications in China surpassed the U.S. starting in 2017.
There are 2 aspects to scientific productivity: the number of publications and the impact of those publications. ScimajoJR calculates a country’s H-index, the number of papers with at least that many citations (Hirsch 2005). For example, an H-index of 100 indicates that a country had 100 publications with at least 100 citations. Figure 28 shows the country H-indices for microbiology, chemistry and biochemistry from 1996–2023 for the top 10 countries publishing in microbiology. The microbiology H-index for the U.S. was nearly 3 times that of China. This indicates that the U.S. produces more high-impact publications. In fact, 5 countries that published fewer papers than China—the U.S., Germany, the United Kingdom, France and Canada—all had higher H-indices than China. The U.S. also had the highest H-index in chemistry and biochemistry. However, China’s H-index was the second highest in chemistry, reflecting the fact that chemistry publications from China have had a longer time to be cited. Biochemistry H-indices look similar to those of microbiology. Three countries that published fewer papers between 1996 and 2003—the U.S., Germany and the United Kingdom—had higher H-indices than China.
Figure 29 shows the rate of country self-citations for the U.S. and China in the 3 disciplines. A country selfcites when it includes a paper produced by authors in the same country in its references. In all 3 disciplines, China is more likely to cite other papers with China-based authors than the U.S. In 2013, microbiology papers originating in China cited 50% of the literature originating in China. By 2023, that rate neared 60%. In contrast, microbiology papers originating in the U.S. cited 40% of the literature originating in the country. This rate went down in the past decade. China self-citation rates are higher in chemistry and biochemistry and have grown more rapidly. In chemistry, China had a self-citation rate of 75% by 2023 compared to a U.S. self-citation rate that was half that size. The biochemistry self-citation rate from China has grown from just over 50% to about 60%. Taken
10The top 10 countries in biochemistry publications from 1996–2023 are in order: China, United States, Japan, Germany, United Kingdom, India, France, Italy, Spain, and Canada.
Figure
together, these results suggest that Chinese researchers are responding to incentives. A recent report indicates that China is incentivizing self-reliance in research publications to reduce expenditures on article processing charges for publications in non-Chinese journals (Owens 2024). However, only about 3% of journals based in China are indexed in Web of Science (Owens 2024). The emphasis on self-reliance in science by China risks the open sharing of research findings that may create separate approaches to research discovery. The emphasis on self-reliance in science by China risks the open sharing of research findings and may lead to the development of separate research paradigms. This could result in 2 divergent sets of research findings: one for China and another for the rest of the world, potentially hindering global scientific collaboration and progress.
Figure 28: Country H-Index by Field, 1996–2023.
Source: ScimagoJR
Figure 29: Country Self-Citations by Field, China and the U.S., 2013–2023.
Source: ScimagoJR
Conclusion
The microbial sciences workforce continues to evolve after the COVID-19 pandemic. Industry is the largest employer, and salaries have increased as demand has stabilized. Compared with chemistry and biochemistry/ biophysics, microbiology doctorates are more likely to change jobs in pursuit of pay and advancement. Analysis of employment by career-stage analysis underscores the growing importance of industry employment at the doctoral level in microbiology, biochemistry and biophysics. Bachelor’s and master’s degree recipients in all 3 fields work predominantly in industry throughout their entire careers.
Using job postings data, our analysis showed that the demand for microbiologists remains robust coming out of the COVID-19 pandemic. Advertised salaries have increased over the past 5 years by about 16% but have remained flat in the past year. Microbiologists continued to work in the same industries between 2014 and 2024, but demand has shifted somewhat. Demand for microbiologists in the pharmaceutical preparation manufacturing industry has dropped considerably, but it has been replaced by an increase in demand in employment placement agencies for clinical microbiologists, as well as for managerial microbiologists in hospitals and physician offices.
Microbiology trains fewer international doctorate students than chemistry and biochemistry/biophysics. Less than 20% of microbiology doctorates come from Asia. In contrast, 35% of chemistry doctorates and 31% of biochemistry/biophysics doctorates are awarded to students from Asia. That said, the share of international microbiology doctorates trained in the U.S. increased to 29% as of 2021. When U.S.-trained microbiology doctorates are employed abroad, they are much more likely than microbiologists employed in the U.S. to be working in academia than in the other fields. Over half of microbiologists employed abroad are working in Asia, but only 2.5% are employed in China.
The growth in microbiology doctorates has increased research in the field. Between 2003 and 2023, publications in microbiology tripled. This was also true in chemistry, but publications in biochemistry grew by only 85% over the past 2 decades. Much of this increase in publications was driven by China. As of 2021, China produced the most publications in microbiology, chemistry and biochemistry/biophysics. However, the U.S. continues to have the most impactful research in all 3 fields, with the highest H-index of all countries considered. Furthermore, China has encouraged citations of research in its own country; the share of country self-citations comes close to 60% in microbiology and exceeds 70% in chemistry. It appears that science in China is branching off from other countries and may become more closed to the international research community.
As the American Society for Microbiology considers the future of the doctoral-trained microbiology workforce, they should keep 2 related trends in mind. In 2021, 42% of microbiology doctorates were employed by industry, whereas only 16% were in tenure or tenure-track academic jobs. Another 19% were in non-tenure-track jobs, including some that involve research and others that do not. The share of microbiologists employed in tenure or tenure-track jobs declined from 22% in 2001. Thus, a smaller share of microbiologists is incentivized to publish their research over time. With fewer research-oriented jobs in the academic departments, U.S. microbiology publications have failed to keep pace with China. Unless more research jobs are created in the future, the U.S. advantage in research impact may also become jeopardized.
References
Heggeness., Misty L., Carlos E. Zambrana, and Donna K. Ginther. 2023. “Workforce Trends: The Future of Microbial Sciences.” Bethesda, MD: American Society for Microbiology.
Hirsch J.E. 2005 Nov 7. “An index to quantify an individual’s scientific research output.” Proceedings of the National Academy of Sciences 102(46):16569–72.
National Institutes of Health. 2023 Dec 15. NIH Advisory Committee to the Director, Working Group on ReEnvisioning NIH-Supported Postdoctoral Training: Report to the NIH Advisory Committee to the Director (ACD) Washington, DC: NIH.
Trapani, Josh and Katherine Hale. 2022 Feb. “Higher Education in Science and Engineering.” Science and Engineering Indicators 2022. NSB-2022-3. Alexandria, VA: National Center for Science and Engineering Statistics (NCSES). Available at https://ncses.nsf.gov/pubs/nsb20223/.
Owens, Brian. 2024. “China’s research clout leads to growth in homegrown science publishing.” Nature 630, S2–S4. SCImago, (n.d.). SJR. SCImago Journal & Country Rank [Portal]. Retrieved May 15, 2024, from http://www. scimagojr.com.
Appendix
Table A1: Skills that are mentioned increasingly in job advertisements, 2024.
Source: Lightcast.