This paper postulates the hypothesis that the stability of the rules under which compete the different interest groups is a relevant consideration to explain economic growth; under this hypothesis it is possible to propose indices that may capture the degree of stability of the rules of the redistributive game better than the usual measures of political stability. We will develop our hypothesis from the interest-groups approach to public policy; approach that can be traced back as early as the beginning of this century when The Process of Government, seminal book written by Arthur Bentley, was first published. In The Process of Government Bentley characterizes the government as a process, in which interest groups are the protagonists. Under this framework an interest group is a certain portion of the members of a society taken as a mass activity, which does not preclude anyone who participate in it from participating inmany other groups. Every person has not one but many interests, the more complex their culture becomes the more interests they will have; in these terms a group and the activity of the group are equivalent. For Bentley, there is no group without its interest; an interest is the equivalent of a group. As the shared interest that defines any group declines, the group itself becomes weak and may even disappear. Interest groups are the raw material to the comprehension of government behavior, and, as we have already stated, they are the protagonists of the process of government. This process is defined as the activity of the groups in their relation with one another; in these terms no group has any meaning except in its relation to other groups. Groups are in constant activity, pressing to one another, cooperating, competing, forming offensive and defensive alliances, splitting apart, and disappearing, with new groups forever being formed. Strong groups dominate, and delineate the existing state of society; state that under this framework have to be appraisal as an equilibrium, given that it is the end result of the pressure exerted by a multiplicity of interest groups. The interest groups theory of government is useful to explain public policies not only under democratic regimes but also under autocratic ones, since it focus on pressure groups instead of voters, politicians and political parties. Under Bentley framework it is no fair to talk of despotisms or democracies as though they were absolutely distinct types of governments. All depends for each despotism and each democracy on the given interests, their relations, and their methods of interaction. Notwithstanding, the political success of particular interest groups is sensitive to the characteristics of the political regime, because they influence the rules under which the groups compete. This feature will prove to be of great relevance in order to develop our hypothesis. In the following section we will illustrate the fact that the type of political regime does not seem to play an important role for economic growth, since neither democracies nor autocracies appear to have definitive advantages from a theoretical, or empirical, point of view. Section 3 will portray the relation between political stability and economic growth. Finally, Section 4 will be devoted to introduce our hypothesis; in direction to this goal we will make use of the interest-groups approach to public policy, and we will propose different indices that may capture the degree of stability of the rules of the redistributive game better than indices of political stability.