The IMF model of the economic transition stresses the role of macro policy reform. It concludes that rapid reform to a market economy is preferable to slow reform because late reformers experience very steep transition recessions and severe contractions in government revenues. However, the predictive power of the IMF model has weakened through the late-1990s. This is because it under-estimates the role of initial conditions that include the natural resource endowment as well as institutional capital and the legacy of produced capital. This paper demonstrates how the predictive power of the IMF model can be improved by taking account of the impact of natural resource abundance for the transition. Resource abundance can feed corruption and diminish the urgency of reform, thereby intensifying the adverse effect of a retarded transition. It can also amplify the contraction of the non-booming tradeable sector due to Dutch disease effects. These adverse features are likely to be more severe where the resource endowment creates point source socio-economic linkages, as in mining, as opposed to the diffuse linkages associated with crop production by yeoman farmers. The detrimental effects of resource abundance are also likely to be more severe where institutional capital is deficient. Consistent with such a resource-constrained variant of the IMF model; resource- abundant Kazakhstan and Uzbekistan both delayed their reforms and both exhibit high levels of corruption relative to the transition economies as a whole. Also, economic recovery in Kazakhstan is slower than the original IMF model predicts because investment in minerals strengthened the exchange rate and retarded economic diversification. In the case of Uzbekistan, a natural resource endowment that yielded especially buoyant crop revenues (that eased the foreign exchange constraint) helps to explain why the growth collapse is less than the unadjusted IMF model predicts for such a slow reformer. This explanation is still too simple, however. Uzbekistan also benefits from robust social capital and limited obsolete industry, both of which retard the decline in government revenue. Finally, the resource-constrained IMF model suggests that the Uzbek policy of gradual reform represses exports and intensifies economic distortions. This will lock the economy into a staple trap and lead to a growth collapse, as the experience of many resource-abundant developing market economies testifies.