On introduit le concept de processus aleatoire vectoriel presque integre. Ce type de processus aide a travailler vers une theorie asymptotique generale de la regression pour des series temporelles multiples

This paper uses cross-sectional and longitudinal data to examine differences in pay for equally-skilled workers in different ind ustries. The major finding is that there is substantial dispersion in wages across industries, even after allowing for measured and unmeas ured labor quality, working conditions, fringe benefits, transitory d emand shocks, the threat of union-ization, union bargaining power, fi rm size, and other factors. In addition, evidence is presented demons trating that turnover has a negative relationship with industry wage differentials. These findings suggest that workers in high-wage indus tries receive noncompetitive rents. Copyright 1988 by The Econometric Society.

This paper utilizes asymptotic expansions of the Edgeworth type to investigate alternative forms of the Wald test of nonlinear restrictions. Some formulae for the asymptotic expansion of the distribution of the Wald statistic are provided for a general case that should include most econometric applications. When specialized to the simple cases that have been studied recently in the literature, these formulae are found to explain rather well the discrepancies in sampling behavior that have been observed by other authors. It is further shown how the corrections delivered by Edgeworth expansions may be used to find transformations of the restrictions which accelerate convergence to the asymptotic distribution.

This paper studies the effects of spurious detrending in regression. The asymptotic behavior of traditional least squares estimators and tests is examined in the context of models where the generating mechanism is systematically misspecified by the presence of deterministic time trends. Most previous work on the subject has relied upon Monte Carlo studies to understand the issues involved in detrending data that are generated by integrated processes and our analytical results help to shed light on many of the simulation findings. Standard F tests and Hausman tests are shown to inadequately discriminate between the competing hypotheses. Durbin-Watson statistics, on the other hand, are shown to be valuable measures of series stationarity. The asymptotic properties of regressions and excess volatility tests with detrended integrated time series are also explored.