This Policy Research Working Paper examines the challenges faced by developing countries in implementing environmental policies, particularly in the context of weak institutions. The authors find that common environmental policies, such as taxes to reduce over-exploitation of natural resources, can be counterproductive when institutions are weak and the general equilibrium effects of such policies are not taken into account. This paradoxical result is due to fundamental mechanisms in structural transformation frameworks and does not require strong assumptions. The paper concludes that environmental policies should be considered within a country's broader development context, rather than in isolation.