In this paper we investigate whether the dynamic properties of the U.S. business cycle have changed in the last fifty years. For this purpose we develop a flexible business cycle indicator that is constructed from a moderate set of macroeconomic time series. The coincident economic indicator is...

In this paper we investigate whether the dynamic properties of the U.S. business cycle have changed in the last fifty years. For this purpose we develop a flexible business cycle indicator that is constructed from a moderate set of macroeconomic time series. The coincident economic indicator is...

Using recently developed structural break tests that are valid for difference-stationary and trend-stationary data and efficient unit root tests that allow for breaks we examine the trend behavior of two air pollutants, Nitrogen Oxides (NOX) and Volatile Organic Compounds (VOC). We find that...