There are different kinds of works councils. They can be cooperative or antagonistic for example. There are also different kinds of management. The managers can be friendly or unfriendly to the workers and the works council representing them. Here the mutual relationship between works council and management is analysed. To this end two data sets are connected, the NIFA-Panel with information about mechanical engineering plants in Germany given by the management and the Bochumer survey of works councils in some of these plants. A new typology of the relationship between the works council and the managers of a firm is derived from these combined data. The effects of a positive, neutral or negative relationship on different turnover rates, product innovations and earnings of the firms are empirically analysed. The results are in accordance with prior studies using only separated data for works councils or management. Concretely, turnover and earnings are mostly lower and innovations more probable as long as any kind of works council exists. The kind of relationship influences the magnitudes of these effects and their statistical significance. A positive relationship reduces the departure rate most of all, a negative relationship has the strongest effect on innovations and, unexpectedly, an inconsistent relationship is best for earnings.