We investigate the effect of lane kilometers of roads on vehicle-kilometers traveled (VKT) in US cities. VKT increases proportionately to roadway lane kilometers for interstate highways and probably slightly less rapidly for other types of roads. The sources for this extra VKT are increases in driving by current residents, increases in commercial traffic, and migration. Increasing lane kilometers for one type of road diverts little traffic from other types of road. We find no evidence that the provision of public transportation affects VKT. We conclude that increased provision of roads or public transit is unlikely to relieve congestion.

We investigate the effect of climate change on population growth in 18th and 19th century Iceland. We find that annual temperature changes help determine the population growth rate in pre-industrial Iceland: a year 1 degree Celsius cooler than average drives down population growth rates by 1.14%. We also find that 18th and 19th century Icelanders adapt to prolonged changes in climate after 20 years. These adaptations reduce the short run effect of annual change in temperature by about 60%. Finally, a 1 degree Celsius sustained decrease in temperature decreases the steady state population by 10% to 26%.

This note corrects an error in an example in Meetings with Costly Participation (AER 90(4), 927-943). It characterizes the set of equilibria for the example under the assumptions in the paper, shows that in all the equilibria an interval of moderate po- sitions is devoid of participants, and provides assumptions under which the result as originally stated is correct.

We study a collective decision-making process in which people interested in an issue may participate, at a cost, in a meeting, and the resulting decision is a compromise among the participants' preferences. We show that the equilibrium number of participants is small and their positions are extreme, and when the compromise is the median, the outcome is likely to be random. The model and its equilibria are consistent with evidence on the procedures and outcomes of U.S. regulatory hearings.