The fluctuation of economic activity around the long-term growth path. A cycle involves a period of above-trend growth of output (recovery and prosperity), and a period of below-trend stagnation or decline (contraction or recession). Cycles of various lengths have been identified. The shortest cycle is the Kitchin inventory cycle (3–5 years). Next follows the Juglar fixed investment cycle (7–11 years)—this is the standard economic cycle. The Kuznets infrastructural investment cycle is even longer (15–25 years). The longest cycle usually identified is the Kondratieff wave (45–60 years). See also endogenous business cycle; political business cycle; real business cycle.