  The central problems of Development Economics are the explanation of the
gross disparities in the global distribution, $\cal{D}$, of economic
performance, $\cal{E}$, and the persistence, $\cal{P}$, of said distribution.
Douglass North argued, epigrammatically, that institutions, $\cal{I}$, are the
rules of the game, meaning that $\cal{I}$ determines or at least constrains
$\cal{E}$. This promised to explain $\cal{D}$. 65,000 citations later, the
central problems remain unsolved. North's institutions are informal, slowly
changing cultural norms as well as roads, guilds, and formal legislation that
may change overnight. This definition, mixing the static and the dynamic, is
unsuited for use in a necessarily time dependent theory of developing
economies. We offer here a suitably precise definition of $\cal{I}$, a
dynamical theory of economic development, a new measure of the economy, an
explanation of $\cal{P}$, a bivariate model that explains half of $\cal{D}$,
and a critical reconsideration of North's epigram.
