John asked in [5169]
> I am not familiar with the efforts of Ehrbar and Glick. Are they published?
> Did they look at the RRI to see if competition kept it "closely in line"?
Yes, it is published in
Mark Glick and Hans Ehrbar,
"Long-Run Equilibrium in the Empirical Study of
Monopoly and Competition,"
Economic Inquiry, vol. 28, no. 1, January 1990, pp. 151--62.
We did not try to measure the RRI but
measured the instantaneous profit rate,
profit over the market value of
the capital stock. We used manufacturing
broken down into two-digit SIC industry classifications.
Our results were that profit rates were
not very different (the better our measures of
profit the more equal they becme), and that there was
an adjustment process going on equalizing them.
Hans Ehrbar.