Although no broad and comparable data base is kept current nowadays, the time may again be ripe. In a number of countries the primary government census records on establishments and firms have now been organized into public- use longitudinal data bases, and these have sustained flourishing programs of new research that contribute bountifully to the fields of industrial organization, labor economics, and macroeconomics. In most countries, these data bases apparently do not conveniently distinguish foreign subsidiaries, or units of domestic firms that also have investments abroad, from the run of domestic firms. Canada is a notable exception, however, and research by Baldwin (1995, esp. chaps. 11, 13) demonstrates the value of being able to follow foreign subsidiaries over time especially in comparison with domestically controlled rivals. Due to disclosure prohibitions the information lurking in these longitudinal data bases cannot easily be linked to longitudinal profiles of MNEs of the HMEP variety, but researchers should be alert to the possibility of a new start in this direction.