Studies analyzing the importance of intra- and inter-regional cooperation for regional innovation performance are mainly of qualitative nature and focus strongly on the positive effects that high levels of cooperation can yield. For the case of the German labor market regions and the Electrics & Electronics industry the paper provides a quantitative-empirical analysis taking into account the possibility of negative effects related to regional lock-in, lock-out, and cooperation overload situations. Using conditional nonparametric frontier techniques and cooperation behavior measures we find positive as well as substantial negative effects of cooperation with the latter being induced by excessive and unbalanced cooperation behavior.