Business-cycle fluctuations in economic activity

This chapter explains what the business cycle is and what causes business-cycle fluctuations. We call fluctuations in economic activity around the long-term growth trend ‘the business cycle’. The business cycle consists of two phases. The first is a period of strong economic activity. The second, following the first, is a period of weak economic activity. We call the first phase of the business cycle an ‘expansion’ and the second phase a ‘contraction’ or ‘recession’. The chapter explains what causes business cycles, and examines the empirical evidence on the lengths and strengths of the typical business cycle. It finds that expansions typically last longer than recessions. The chapter also shows that the length of expansions has increased during recent decades.