We assess the finite sample performance of the conduct parameter test in
homogeneous goods markets. Statistical power rises with an increase in the
number of markets, a larger conduct parameter, and a stronger demand rotation
instrument. However, even with a moderate number of markets and five firms,
regardless of instrument strength and the utilization of optimal instruments,
rejecting the null hypothesis of perfect competition remains challenging. Our
findings indicate that empirical results that fail to reject perfect
competition are a consequence of the limited number of markets rather than
methodological deficiencies.Comment: 8 pages, 3 appendi