Does output have a unit root? New international evidence

In this paper unit-root tests for per capita output of 12 OECD countries are performed. Using traditional unit-root tests, it follows that the unit-root hypothesis cannot be rejected except for the US. However, following the approach of Perron (1989), which takes shifts in mean and/or trend into account, the null hypothesis of a unit-root can be rejected in most countries in our sample. In contrast to Perron, a method suggested by Christiano (1992) is used to determine the break date endogenously.