Overall productivity and profitability declined for German codetermined firms that went from 1/3 to 1/2 parity from 1975 - 1983.

"The change from one-third to almost-parity seems to have had a consistently negative effect on productivity and profitability, but little influence on labour cost, in our sample of 68 mostly very large corporations in comparison with a control group of 44 smaller firms."

empirical