Aprovision of the Food, Conservation, and Energy Act of 2008 requires country of origin labeling (COOL) for certain agricultural commodities. To comply with the law, producers, processors, and retailers face additional production costs associated with labeling, separating, and tracking commodities. Using estimated costs provided by the U.S. Department of Agriculture's Agricultural Marketing Service (AMS), we simulate the impacts of mandatory COOL on U.S. and global agricultural markets using a global static general equilibrium model (STAGEM). The results show resource adjustments that lead to decreases in production, consumption, and trade flows. The results assume no demand premium for labeled commodities relative to unlabeled commodities. Key Words: country of origin labeling, agricultural trade, global general equilibrium (ProQuest: ... denotes formulae omitted.) Aprovision in the Farm Security and Rural InvestmentAct of 2002 (2002 FarmAct) required certain commodities-beef, pork, lamb, fish and shellfish, fruits and vegetables, and peanuts-sold at the retail level to be identified by their country of origin label (COOL). In a 2004 ruling, regulations were published to implement COOL for fish and shellfish. The regulations became effective inApril 2005. Congress responded to growing criticisms of the program by extending the comment period and allowing further debate on the COOL provision for the remaining commodities. This resulted in a delay of mandatory COOL for the remaining covered commodities. The Food, Conservation, and Energy Act of 2008 (2008 Farm Act) amended the COOL provisions. Goat meat, poultry, macadamia nuts, ginseng, and pecans were added as commodities covered by mandatory COOL. Regulations for all covered commodities were published in August 2008, and COOL provisions were implemented on September 30, 2008. The U.S. Department of Agriculture's Agricultural Marketing Service (USDA-AMS) issued a final ruling for COOL on January 15, 2009 (Federal Register 2009). It became effective on March 16, 2009. COOL increases the cost of production for covered commodities through increased labeling, separating, and tracking costs. This affects production along the entire supply chain, including imported commodities. Cost increases are likely to lead to decreases in the production of covered commodities, both domestic and imported, and to higher commodity prices. Cost estimates for implementing COOL in the impacted sectors of the supply chain are provided by theAMS (see Federal Register 2008). We use a global static general equilibrium model (STAGEM) to evaluate market responses and resource adjustments to mandatory COOL. The STAGEM model reflects world markets as they were in 2004. We employ the widely accepted equivalent variation (EV) method to measure social welfare gains or losses due to mandatory COOL. The EV measurement of welfare uses status quo (pre-policy) prices as a base and addresses the question: What change in income at the current prices would be equal to the change brought about by the policy in terms of the impact on utility? (Varian 1992) Our welfare indicator accounts for producer and consumer welfare, capturing economy-wide resource reallocation and adjustment due to mandatory COOL. However, our results assume no consumer preference for mandatory COOL relative to no labeling system. Given the cost assumptions developed by AMS (see Table 1), we find that the mandatory COOL provision reduces overall U.S. welfare through its impacts on commodity and downstream processing markets.We show that the costs of complying with mandatory COOL are likely to lead to decreases in agricultural production and increases in agricultural prices. Global market impacts are also reported, with trade volume and global welfare declining. Again, these results assume no consumer preferences for country of origin labeled commodities. Given the uncertainty of consumer responses to mandatory COOL, we model only the impacts of increased costs (as provided by AMS) on both consumers and producers due to COOL implementation. …