National natural rates of interest and the single monetary policy in the euro area
估计了1999-2016年欧元区四大经济体的国家自然实际利率，发现2008年后平均自然利率下降，主权危机期间南欧国家自然利率显著为负，且各国利率缺口出现分化，但2014年后随着欧洲央行非常规政策推进，共同政策立场得以恢复。
Summary We estimate time‐varying national natural real rates of interest ( r ∗ ) for the four largest economies of the euro area over 1999–2016. We further derive the associated national real interest rate gaps, which gauge the perceived monetary policy stance in each country. We find that the average r ∗ have been lower after 2008. Furthermore, national r ∗ were significantly negative in southern countries during the sovereign crisis. As their effective real rates soared, national rate gaps across the euro area diverged. However, a common policy stance has been restored since 2014 as the European Central Bank's unconventional programs gathered pace.