We provide the planner's solution to a model where households learn from exogenous natural disaster arrivals about arrival rates and spend to mitigate future damages. Mitigation cannot be decentralized due to positive externalities from curtailing aggregate risks. First-best can be implemented...

Aging populations in advanced economies are placing ever-increasing demands on government spending in the form of old-age benefits. Economies that have promised substantially more benefits than they have made provision to finance are heading into a prolonged era of fiscal stress. Unresolved...

International environment and development agencies increasingly emphasize external cofinancing when selecting projects to fund. This paper considers whether the emphasis on cofinancing helps promote institutional objectives, or creates perverse and inefficient incentives. We present a model of...

Cities generate negative, as well as positive, externalities; addressing those externalities requires both infrastructure and institutions. Providing clean water and removing refuse requires water and sewer pipes, but the urban poor are often unwilling to pay for the costs of that piping....

Poor water quality and sanitation are leading causes of mortality and disease in developing countries. However, interventions providing toilets in rural areas have not substantially improved health, likely because of incomplete coverage and low usage. This paper estimates the impact of an...

We study the extent to which collusion can explain the under-provision of clean sanitation technologies in developing countries. Using desludging services in Dakar as a case-study, we document that prices are 66% higher in areas where prices are likely coordinated by a large trade association,...

This paper examines the association between episodes of large fiscal impulses (expansions and adjustments) and sustainable development indicators (prosperity, resilience, and inclusivity). We provide country studies of Chile, Poland, South Africa, and Thailand, examining the components of...

We view sustainability as a requirement that welfare should not be expected to decline over time. We impose this requirement as a prior constraint on the consumption-savings-investment problem, and study its implications for saving, risky investment, and the social discount rate. The constraint...

How does the sustainable level of consumption depend on productivity growth and the size and growth rate of the population? What is the effect of uncertainty over these growth rates? I address these questions using a model in which productivity and population growth are stochastic, and social...