Matthew Lilley is a PhD candidate at the Harvard Economics Department and Harvard Business School. His research interests are primarily in behavioral economics and political economy.
Matthew Lilley is a PhD candidate at the Harvard Economics Department and Harvard Business School.
Prior to this, he received a B. Economics (Honours) from the University of Sydney in 2012. He worked in the Research Department at the Reserve Bank of Australia, and then as a research assistant for Economics faculty at the University of Sydney and University of New South Wales.
His research focuses on behavioral economics and political economy, and other topics in empirical microeconomics. His recent research includes work on the role of peer effects on how US Supreme Court justices vote, and gender differences in blood donation.
High-profile disasters can cause large spikes in philanthropy and volunteerism. By providing temporary positive shocks to the altruism of donors, these natural experiments help identify heterogeneity in the distributions of the latent altruism which motivates donors. This study examines gender heterogeneity of volunteer response by blood donors following the most devastating Bushfires in Australia's history. Using difference in differences analyses, we observe a sharp increase in blood donations after the 2009 Victorian Bushfires. Several key features of this increase are consistent with the predictions of a model where the distribution of latent altruism has smaller variance among women than men. First, the highest increase in donations occurs among previous non-donors, lapsed donors and less frequent donors. Further, the increase in donations following the Bushfires, compared to non-disaster periods, is substantially greater for females than males; the proportional increase in the number of females donating for the first time after the disaster is approximately twice the proportional increase for men. Notably, this gender gap decreases with the frequency with which people have previously donated.
Using data on essentially every US Supreme Court decision since 1946, we estimate a model of peer effects on the Court. We consider both the impact of justice ideology and justice votes on the votes of their peers. To identify these peer effects we use two instruments. The first is based on the composition of the Court, determined by which justices sit on which cases due to recusals or health reasons for not sitting. The second utilizes the fact that many justices previously sat on Federal Circuit Courts and are empirically much more likely to affirm decisions from their “home” court. We find large peer effects. Replacing a single justice with one who votes in a conservative direction 10 percentage points more frequently increases the probability that each other justice votes conservative by 1.63 percentage points. In terms of votes, a 10 percentage point increase in the probability that a single justice votes conservative leads to a 1.1 percentage increase in the probability that each other justice votes conservative. Finally, a single justice becoming 10% more likely to vote conservative increases the share of cases with a conservative outcome by 3.6 percentage points – excluding the direct effect of that justice – and reduces the share with a liberal outcome by 3.2 percentage points. In general, the indirect effect of a justice’s vote on the outcome through the votes of their peers is typically several times larger than the direct mechanical effect of the justice’s own vote.
