Are Recoveries all the Same: GDP and TFP?*
研究了美国二战后经济衰退后的复苏形状（U型或L型），发现早期衰退多为U型，近期多为L型，且全要素生产率在所有衰退后都快速恢复。
Abstract Recessions and subsequent recoveries are frequently classified as ‘L‐shaped’ or ‘U‐shaped’, with output losses in the former being permanent and losses in the latter at least partially made up by higher than average growth during the recovery. We estimate the probability of a U‐shaped recovery for postwar NBER recessions. Most earlier recessions were U‐shaped but more recent recessions have been L‐shaped. The shape of recoveries is tracked relatively well by durable consumption, investment, labour hours and employment. Posterior probabilities for the shape of recoveries for nondurable consumption and participation rate are less decisive. However, total factor productivity appears to recover rapidly after all recessions.