This paper examines the relationship between policy uncertainty and private investment in developing countries. It argues that even moderate levels of policy uncertainty can significantly hinder private investment, which is crucial for sustainable recovery in heavily indebted developing countries. The paper develops a simple model to show how uncertainty about the future of policy reforms can act as a tax on investment, even when entrepreneurs are risk-neutral. The model highlights that the success of policy reforms depends not only on their economic merits but also on the perceived likelihood of their survival. If the probability of policy reversal is high, the reform may fail to attract investment, even if it is otherwise sensible. The paper discusses how uncertainty can lead to a self-fulfilling pessimism, where expectations of policy reversal cause investors to withhold capital, further reinforcing the uncertainty. It also explores the implications of this for policy design, emphasizing the need for policy stability and sustainability to encourage private investment. The analysis shows that reforms that are too gradual may not be effective due to the hysteresis effects of investment decisions. However, if reforms are large enough and accompanied by sufficient policy stability, they can attract investment and lead to sustainable growth. The paper also discusses the empirical evidence linking policy uncertainty to private investment, citing studies that show negative relationships between economic instability and investment and growth. It concludes that policy stability is essential for attracting private investment and promoting economic growth in developing countries. The paper underscores the importance of credible and sustainable policy reforms in fostering a favorable investment climate.This paper examines the relationship between policy uncertainty and private investment in developing countries. It argues that even moderate levels of policy uncertainty can significantly hinder private investment, which is crucial for sustainable recovery in heavily indebted developing countries. The paper develops a simple model to show how uncertainty about the future of policy reforms can act as a tax on investment, even when entrepreneurs are risk-neutral. The model highlights that the success of policy reforms depends not only on their economic merits but also on the perceived likelihood of their survival. If the probability of policy reversal is high, the reform may fail to attract investment, even if it is otherwise sensible. The paper discusses how uncertainty can lead to a self-fulfilling pessimism, where expectations of policy reversal cause investors to withhold capital, further reinforcing the uncertainty. It also explores the implications of this for policy design, emphasizing the need for policy stability and sustainability to encourage private investment. The analysis shows that reforms that are too gradual may not be effective due to the hysteresis effects of investment decisions. However, if reforms are large enough and accompanied by sufficient policy stability, they can attract investment and lead to sustainable growth. The paper also discusses the empirical evidence linking policy uncertainty to private investment, citing studies that show negative relationships between economic instability and investment and growth. It concludes that policy stability is essential for attracting private investment and promoting economic growth in developing countries. The paper underscores the importance of credible and sustainable policy reforms in fostering a favorable investment climate.