Do Foreign Firms Really Pay Higher Wages? Evidence from Different Estimators
Pedro S Martins
October 2004
Abstract
We contribute to the literature on Foreign Direct Investment and labour markets by examining
wage differentials between domestic and foreign firms, drawing on a large Portuguese matched
employer-employee panel. Using OLS, the foreign-firm premium is large and significantly
positive but falls substantially when firm and worker controls are added. Moreover, the premium
also does not vary monotonically with foreign control, increases along the wage distribution and
is generally insignificant when using propensity score matching (PSM). Finally, using
differences-in-differences (DID), we find lower wage growth for workers in domestic firms that
are acquired by foreign investors, a result that holds when combining DID and PSM. Overall,
our evidence suggests that the commonly-documented OLS premium cannot be interpreted as a
causal impact.
JEL codes: C23, F23, J31.
Keywords: FDI, Wages, Matched Employer-Employee Data, Propensity Score Matching,
Portugal.