My dissertation encompasses two distinct lines of research related to environmental economic and industrial organization. In the first chapter, I measure the different driving behavior between high and low efficiency NYC taxi drivers. Fuel efficiency has improved because of environmental policies and high gas prices. In most cases, increased vehicle usage is associated with negative outcomes because of potentially increasing emissions. In the New York City (NYC) taxi industry, however, increased vehicle usage corresponds to increased supply, which is meaningful because of limits on the number of permissions and the fixed fare system. I estimate the impact of fuel efficiency improvement on the driving behaviors of NYC taxi drivers by using ...