The economic impacts of a gypsy moth infestation on homeowners and on managers of recreation areas (commercial, public, and quasi-public) were determined from data collected via interviews with 540 homeowners and 170 managers of recreation areas in New York and Pennsylvania. The approach to measuring the impact of gypsy moth was to determine the interaction of a specific effect of an infestation (tree defoliation, tree mortality, nuisance) with a specific ownership objective (the reason a person has for owning or managing a property). Data were also collected on costs of controlling the gypsy moth, on financial losses resulting from infestation, and on person-days of recreational use of property lost by ownership class.