This article focuses on the political factors underpinning economic growth and the development of markets – not simply the rules governing economic exchange, but also the institutions governing how these rules are enforced and how they may be changed. A critical political factor is the degree to which the regime or sovereign is committed to or bound by these rules. Rules the sovereign can readily revise differ significantly in their implications for performance from exactly the same rules when not subject to revision. The more likely it is that the sovereign will alter property rights for his or her own benefit, the lower the expected returns from investment and the lower in turn the incentive to invest. For economic growth to occur the sovereign or government must not merely establish the relevant set of rights, but must make a credible commitment to them.

A ruler can establish such commitment in two ways. One is by setting a precedent of “responsible behavior,” appearing to be committed to a set of rules that he or she will consistently enforce. The second is by being constrained to obey a set of rules that do not permit leeway for violating commitments. We have very seldom observed the former, in good part because the pressures and continual strain of fiscal necessity eventually led rulers to “irresponsible behavior” and the violation of agreements. The latter story is, however, the one we tell.