Cointegration requires all the variables in the system to have exact unit roots; accordingly it is conventional for researchers to test for a unit root in each variable prior to a cointegration analysis. Unfortunately, these unit root tests are not powerful. Meanwhile, conventional cointegration...

This paper was prepared for the meeting of the Panel on International Capital Transactions of the National Research Council (National Academy of Sciences), April 23, 1992. There are well-documented inadequacies in the data on U.S. international capital flows, cross-border holdings of assets, and...