20091209 School Buses, Diesel Emissions, and Respiratory Health
School Buses, Diesel Emissions, and Respiratory Health
Timothy K.M. Beatty and Jay P. Shimshack*
September 2008
Timothy K.M. Beatty
Department of Economics
University of York
tb526@york.ac.uk
ABSTRACT
School buses pollute near schools and residential areas, they are
disproportionately dirty, and their emissions concentrate within buses. We examine the
impact of school bus emissions programs on health outcomes. We make three
contributions. First, we examine acute pollution reductions. Previous analyses of ambient
air pollution miss important local effects. Second, we study rich program and health data.
Third, we leverage a clean natural experiment to transparently establish causality. We
find that school bus retrofits induced reductions in bronchitis, asthma, pleurisy, and
pneumonia incidence for sensitive populations. Back of the envelope calculations suggest
a benefit-cost ratio of more than 20:1.
JEL I18, Q58, Q53