Okun's law revisited: a threshold in regression quantiles approach

This article proposes, for the first time, a threshold in regression quantiles approach to the analysis of Okun's law. By applying to US data over the 1948Q1-2016Q4 period, we have three major findings. First, a single threshold is detected for both multiple and individual quantiles cases. However, the effect of threshold nonlinearity is only present in the middle to upper quantiles of the conditional unemployment distribution in the individual quantiles case. Second, the first-order autoregressive coefficients of unemployment are significantly larger in the lower-growth regime, indicating that shocks to unemployment appear to be more persistent during recessions. Finally, the Okun's coefficients are all negative across the recessionary and expansionary regimes, confirming the validity of Okun's law. Moreover, the Okun's coefficients are smaller (more negative) in the lower-growth regime, suggesting that the effect of differenced output on differenced unemployment is asymmetric, and is more pronounced in recessions.