internal and external labor markets an analysis of matched longitudinal employer employee data by john m abowd francis kramarz june 1997 is professor economics at cornell university a research associate the national bureau economic head department crest cnrs institut de la statistique et des etudes economiques insee in paris france authors are grateful for support united states science foundation grants sbr 91 11186 93 21053 département recherche centre en economie used this paper confidential but access not exclusive other researchers interested using these should contact ensae 15 bd gabriel péri 92245 malakoff cedex abstract we decompose real annual full time compensation costs 1 million french workers followed over 12 years into part that reflects their opportunity wage rate components