TY - JOUR AU - Leamer,Edward E. TI - The Life Cycle of US Economic Expansions JF - National Bureau of Economic Research Working Paper Series VL - No. 8192 PY - 2001 Y2 - March 2001 UR - http://www.nber.org/papers/w8192 L1 - http://www.nber.org/papers/w8192.pdf N1 - Author contact info: Edward E. Leamer John E. Anderson Graduate School of Management UCLA Box 951481 Los Angeles, CA 90095-1481 Tel: 310/206-1452 Fax: 310/825-4011 E-Mail: edward.leamer@anderson.ucla.edu AB - Graphs that allow side by side comparisons of the six longer US expansions since 1950 suggest that these expansions have four distinct phases: (1) a high growth recovery during which the rate of unemployment declines to its pre-recession level, (2) a modest growth plateau during which the rate of unemployment is constant, (3) a growth spurt that drives unemployment down further and (4) a second plateau with modest growth and constant rate of unemployment. There have been only three expansions that have experienced the spurt and none has experienced a second spurt. These phases involve substantially different rates of GDP growth, but within each of these four phases GDP growth is largely unpredictable. Forecast accuracy thus comes mostly from understanding the transitions. This requires both data and economics. The economics takes the form of a predator/prey model of the cycle, where the prey are investment opportunities and the predators are entrepreneurs. A probit model of the transition into recession raises concerns about how much longer the aged Bush/Clinton expansion can last. ER -