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THE ECONOMICS OF UNIQUENESS
the city and site management. First, it allows comparison of visitor flows across the city; second, it provides data in case a city wants to evaluate the opportunity of imposing limits due to the carrying capacity of a site, or for the purpose of considering entry charges. Additional indicators for visits can be used for mapping. Carrying capacity of a site (i.e., maximum possible number of visitors per day) and visitor rate (i.e., number of visitors as a percentage of carrying capacity) are useful tools to describe the “visit market” of the historic city core. Derived from a straightforward demand-supply relationship, the indicator of visitor rate highlights excess of demand (hence, a risk for the heritage) or excess of supply (hence, a potential for economic values). As noted earlier, use values related to visitors and tourism are of two types: direct use values (i.e., visits to the site, museum, or monument) and indirect use values (i.e., expenditures made by visitors or tourists on lodging, food, and souvenirs). Indirect use values are the most complex to identify, to measure, and to map. Indirect use values are measured by heritage-related expenditures made by residents or visitors. Some of these expenditures are easily traceable and can be inscribed on maps, because they are specifically and completely related to the heritage (a museum of the monument, a souvenir shop, and such). Other expenditures are more difficult to assess, or must be estimated as average values for entire blocks, streets, city areas, or meaningful economic areas. When specific places can be identified or located with precision, the mapping of indirect use values consists of an exhaustive recording and documenting of all such places across the city. This requires extensive gathering of information from hotels, restaurants, shops, visitor information centers, transportation services, guide agencies, and such, which is a task probably applicable to only a small city or a district. Big cities have staff, equipment, and resources to undertake such recording, but the economic impact measured is not exclusively related to the heritage. The need for measurement by sampling is inevitable. Modern technology (e.g., GIS, GPS, Geocoding) will soon offer ways of better managing tourism in historic city cores. These tools will improve site management and prevent congestion where cities struggle with excess tourism. Similar mapping techniques will help city authorities increase the economic impact from tourism. Assessing indirect use values requires relying on both sampling and mapping. Tourist expenditures for lodging, food, transportation, and goods or services are market transactions defined by a supply and a demand side. Appraisal of these transactions can be two-fold: • A demand-side analysis is undertaken through a sample survey among visitors, to analyze the consumer’s behavior and to estimate expenditures per person, per day. Expenditures can also be segmented between per-day trip and