Utilizing an ex-post-facto experimental design, all occupied households located within the rural area of Canton San Carlos in Costa Rica (La Fortuna) were studied in August of 1972 for purposes of testing the hypothesis that electricity use is positively associated with level of living. Interviews with 452 heads of households (when possible) provided information on household members' age; sex; occupation and education; migration and propensity to migrate; mass media exposure; occupation and employment; land use and ownership; level of living; social participation and satisfaction with life situation. Based on data derived from the San Carlos Rural Electric Cooperative records and interviewer observations, electricity user categories were established as follows: (1) users (persons who had access to electricity and used it); (2) non-adopters (persons who had access to electricity but did not use it); and (3) inaccessibles (persons who were beyond the reach of power distribution lines). Controlling for size of household, education of household head, age of household head, and size of farm, Belcher's 1972 level of living scale was employed for analysis. Data supported the hypothesis, and it was suggested that consideration be given to the implications for developmental investment decisions and further research. (JC)