We present the first panel estimates of the productivity effects of the unique German institution of parity, board-level co-determination. Although our data span two severe recessions when labour hoarding costs of co-determination are probably highest, and the panel is too short to capture the likely long-run benefits in terms of human capital formation and job satisfaction, we find positive productivity effects of the 1976 extension to parity co-determination in large firms. Copyright Blackwell Publishing Ltd/London School of Economics 2005.