come from outside the area, and perhaps subscribe to a different—sometimes radically different—culture. Most students are young people, whose living habits may be different from older people. Economically, the high spending power of the university and of its students in aggregate may inflate the cost of living above that of the region. It is common for university employees to commute from surrounding areas, finding the cost of living in town too expensive. "Studentification," in which a growing student population move in large numbers to traditionally non-student neighborhoods, may be perceived as a form of invasion or gentrification. It may be due to university enrollment expanding beyond the capacity of on-campus housing, inadequate zoning enforcement, and/or student culture. Neighborhood associations may work to limit conversion of family homes to student rentals, while some local residents may oppose the construction of large on-campus dormitories or expansion of fraternity and sorority houses, forcing a growing enrollment to seek housing in town. Moreover, a single-family home can be converted into several smaller rental units, or shared by a number of students whose combined resources exceed those of a typical single-family rental—a strong incentive for absentee landlords to cater to students. In the US, educational institutions are often exempted from local taxes, so in the absence of a system for payments in lieu of taxes, the university population will disproportionately burden parts of the local public infrastructure, such as roads or law enforcement. Some analysts argue that students relieve the burden on other parts of the local public infrastructure, such as local primary and secondary schools, by far the most costly line item in most North American city and town budgets, by providing tax revenues through local sales tax and property tax paid by landlords. When a university expands its facilities, the potential loss of property tax revenue is thus a concern, in addition to local desire to preserve open space or historic neighborhoods. As a result, local people may resent the university and its students. The students, in turn, may criticize the local residents' taking jobs at the university provided by student tuition and fees, and accepting the tax revenues (e.g. local sales tax, property tax on rented properties) that students generate, but resenting students' lifestyles. Some students refer to other inhabitants as "townies", a term with somewhat derogatory connotations. This "town and gown" dichotomy notwithstanding, students and the outside community typically find a