In medium- and large-sized cities, such as cincinnati, indianapolis, chicago, and new york, many residents have been getting rid of their cars. keeping a car in a city can be very expensive and quite a hassle due to a lack of parking and strong parking regulations that lead to expensive tickets for even minor parking infringements. residents have learned that they can join services, such as zipcar, that allow them to "borrow" cars from a fleet when they need them. they pay a monthly fee for the service, and they use an online application to "reserve" a car for when they need it. all of the hassle is gone; the car is ready for them when they need it; and parking is always guaranteed. zipcar and other companies like it are examples of

The business cycle is the periodic but irregular up-and-down movement in economic activity, measured by fluctuations in real gross domestic product (gdp) and other macroeconomic variables. a business cycle is typically characterized by four phases—recession, recovery, growth, and decline—that repeat themselves over time. economists note, however, that complete business cycles vary in length. the duration of business cycles can be anywhere from about two to twelve years, with most cycles averaging six years in length. some business analysts use the business cycle model and terminology to study and explain fluctuations in business inventory and other individual elements of corporate operations. but the term "business cycle" is still primarily associated with larger (industry-wide, regional, national, or even international) business trends.