Lynne Kiesling sketched an interesting idea for antitrust enforcement.

prosecutions based on the use of lobbying, regulation, and political relationships (i.e., rent seeking) to deter entry.

Economists traditionally have evaluated monopoly power using measures such as the Herfindahl index of concentration. Kiesling is suggesting that only industries with monopoly power will spend resources lobbying Washington to protect their positions, so that use of such resources can be used as an indicator.

For Discussion. What practical difficulties are there in using political expenditures as an indicator for antitrust enforcement?