We analyze the dramatic decline of the employment share of unskilled labor in the West German economy, in particular its relation to the relatively rigid earnings structure. We find that the substitution elasticity between unskilled and skilled labor is rather low in most sectors of the economy....

This paper demonstrates that insiders can erect barriers to entry and skim rents by sinking costs in human capital when labour markets are otherwise perfectly contestable. The sunk costs nature of human capital investments may result from the need to satisfy ever increasing specialised skill...