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...

Green growth is about making growth resource-efficient, cleaner and more resilient without slowing it. This paper aims at clarifying this in an analytical framework and proposing foundations for green growth. This framework identifies channels through which green policies can potentially...

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,...

Starting in 2009, the German state of Saxony distributed sports club membership vouchers among all 33,000 third graders in the state. The policy's objective was to encourage them to develop a long-term habit of exercising. In 2018, we carried out a large register-based survey among several...

Climate modelers have recognized the possibility of abrupt climate changes caused by a reorganization of the North Atlantic's current pattern (technically known as a thermohaline circulation collapse). This circulation system now warms north-western Europe and transports carbon dioxide to the...

The paper develops a general methodology for analyzing policies with path-dependency (hysteresis) in stochastic models with forward looking optimizing agents. Our main application is a macro-climate model with a path-dependent climate externality. We derive in closed form the dynamics of the...

Green assets delivered high returns in recent years. This performance reflects unexpectedly strong increases in environmental concerns, not high expected returns. German green bonds outperformed their higher-yielding non-green twins as the "greenium" widened, and U.S. green stocks outperformed...

Carbon taxation is a widely proposed and in some countries already adopted means to limit anthropogenic climate change. This paper studies carbon taxation using an 18-region, 80- period overlapping generations model. We focus on carbon policy that delivers present and future mankind the highest...