Economists most time,if not all,derive production efficiency from activities engaged in during the working time,instead of the leisure time.Sociologists,on the other hand argue that the leisure time has a dual role in the production process in that it not only acts as a substitute to working time but can also improve production efficiency through its effects on affecting individuals’ self-development.Using empirical data from nineteen OECD countries the paper finds that:leisure time is nonlinearly associated with economic efficiency,which is defined as GDP per capita per work hour.The leisure time which,despite playing a negative role in economic efficiency at the beginning,turns out to enhance economic efficiency as economy development proceeds.