Causes of haze and its health effects in Singapore; a replication study

Intermittently Singapore suffers from severe air pollution in periods of intense forest and peatland fires on neighboring South-Asian islands. A recent American Economic Review article modeled the causal relationships between fire intensity in Indonesia and air pollution (PSI) in Singapore, and between PSI and health clinic visits in Singapore. We find serious flaws in the quantitative assessment of these relationships. Attempts are made to repair these using the same classic methodology and data, but also by alternative methods requiring less speculative assumptions. Although actually more detailed data are required, also some results are produced which seem more credible.