Roughly 500,000 hectares of forest are lost yearly in Mexico, a country with one of the highest levels of biodiversity worldwide and a large rural poor population. Community forestry is widely viewed as an appropriate development model for Mexico's pine-oak forests, promising economic benefits for local people and an alternative to deforestation. Yet little research has questioned if and how community forestry initiatives contribute to reducing deforestation. In addition, little common property research addresses the effects of external social, economic, and institutional forces on commons management. Mexico provides a perfect natural experiment to explore these issues because of the length of time that widespread community forestry has existed. I propose to research whether and under what conditions community forestry in Mexico is reducing deforestation, focusing on three themes: I am currently analyzing the effectiveness of community forestry in reducing deforestation compared to other macro-level social and economic factors in the states of Oaxaca, Guerrero, Michoacan, and Durango through multivariate regressions, using deforestation rates as a dependent variable and municipalities as the unit of analysis. (2) In my fieldwork, I will measure how variations in the strength of community management affect deforestation rates through satellite imagery and a survey of 40 communities in two municipalities in Michoacan and Guerrero. (3) Finally, I will conduct a comparative case study of exogenous institutional, historical, and political factors on the implementation of community forestry in these two municipalities. I defined these foci during preliminary research conducted in the summer of 2004 in Mexico. Results will aid in better targeting development programs to underlying social, economic, historical, and institutional causes of deforestation and will help explain the relative influence of these factors within common property theory.