Distance is converted into currency using average cost per km estimates. We estimate that USD 0.15 per km is a reasonable measure of the travel costs in Costa Rica in 1988. This estimate in- cludes out-of-pocket costs, a fraction of fixed costs, and the value of travel time (8). Since consumer surplus is directly pro- portional to cost per km, the reader can easily adjust our estimates using any de- sired cost per km figure. For example, at USD 0.30 per km, the consumer surplus estimates would be twice as high as those reported here