[영문]The influence of informal institutions on economic outcomes forlow income individuals and households has received little attentionin the United States. Yet, drawing on social capital theoryand existing studies from developing countries where informalinstitutions have been widely used in promoting economic opportunitiesof families in poverty, one would expect these institutionsto have positive effects on the economic outcomes of low incomeindividuals in the context of an IDA program. Using a sample of840 respondents who were enrolled in a community action program,this study assesses the effects of informal networks of socialsupport on performance in a matched savings program. Resultsshow partial support for the hypothesized relationship. Specifically,an increase in the amount of help a respondent gives to membersof her community is inversely related to performance in anIDA program. This may imply that although informal networkshave mutual benefits for both the individual and community, economicallythese benefits may be mixed. Among low income individualssaving in an IDA program, participating in such networksmay constrain the economic resources available to them ortheir households; hence impacting their performance negatively.