Labor market theories that allow for search frictions make marked predictions on the effect of these frictions on wages. Often, the effect is predicted to be negative. Despite the popularity of these theories, this has never been tested. We perform tests with matched worker-firm data. We compare different markets with different degrees of frictions and different market outcomes. The matched data allow for an assessment of the skill composition in different markets. This allows us to investigate how the mean difference between labor productivity and wages in a market depends on the degree of frictions and other determinants. We perform separate analyses for The Netherlands and Denmark.