Learning efficiency shocks, knowledge capital and the business cycle: A Bayesian evaluation
本文将学习效率冲击引入标准DSGE模型，利用美国战后数据发现，这类冲击是产出、投资、消费尤其是工时波动的重要来源，且能减少对偏好和全要素生产率外生变动的依赖。
Abstract We incorporate shocks to the efficiency with which firms learn from production activity and accumulate knowledge into an otherwise standard real DSGE model with imperfect competition. Using real aggregate data and Bayesian inference techniques, we find that learning efficiency shocks are an important source of observed variation in the growth rate of aggregate output, investment, consumption and especially hours worked in post‐war US data. The estimated shock processes suggest much less exogenous variation in preferences and total factor productivity are needed by our model to account for the joint dynamics of consumption and hours. This occurs because learning efficiency shocks induce shifts in labour demand uncorrelated with current total factor productivity (TFP), a role usually played by preference shocks that shift labour supply. At the same time, knowledge capital acts like an endogenous source of productivity variation in the model. Measures of model fit prefer the specification with learning efficiency shocks. The results are robust to the addition of many observables and shocks.