The one constant : a causal effect of collective bargaining on employment growth? ; evidence from German linked-employer-employee data

A large number of articles have analysed ‘the one constant´ in the economic effects of trade unions, namely that union bargaining reduces employment growth by two to four percentage points per year. Evidence is, however, mostly related to Anglo-Saxon countries. We investigate whether a different institutional setting might lead to a different outcome, making the constant a variable entity. We use linkedemployer-employee data for Germany and analyse the effect of collective bargaining coverage on employment growth in German plants. We find a robust and negative correlation between being covered by a sector-wide bargaining agreement or firmlevel contract and employment growth per annum of about 0.8 percentage points. Using various approaches, however, we cannot establish a causal interpretation of the effects, suggesting that the cross-section results are driven by selection.