Set 4, EEP 145 Due: April 25 1. T/F Moretti and Neidell (2011) use variation in pollution levels induced by ship arrivals in the Los Angeles ports to estimate the effect of air pollution on hospitalizations. In essence, they compare the number of hospitalizations on days when there is a high level of ship activity to the number of hospitalizations on days when there is a low level of ship activity. However, their estimates must be biased if high pollution days are concentrated during the summer, because we know from the Deschenes and Moretti (2009) paper that mortality rates (and presumably hospitalizations) are lower during the summer