Colombia is among the three largest coca leaf producers and the world's leading supplier of cocaine to the US (UNODC, 2009). The US and Colombia have aggressively pursued forced coca eradication and introduced an anti-drug policy named Plan Colombia (PC) to combat cocaine production. This paper examines the effects of the strategies for controlling coca supply in Colombia on the value of the agricultural output. For this purpose, the study exploits the main changes in the policy used by the

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... mbian government under PC to reduce cocaine supply as an exogenous variation in coca cultivation to the value of legal agricultural production. The empirical strategy follows a (triple) difference-in-differences (DID) estimator by assessing whether changes in the PC strategy to reduce coca cultivation affect the value of agricultural production disproportionately in coca-growing areas. The results indicate an increase in the legal agricultural GDP due mainly to the interdiction of cocaine and cocaine-processing facilities policy in Colombia since 2007. Coca-growing areas of Colombia saw substantial drops in cultivation from 2007 to 2013 and benefited from such policy compared to agriculture in non-coca-growing regions. The results also indicate that the value of agricultural production in the coca-growing areas gained a monetary benefit from the cocaine labs' dismantling policy of about US$284.2 million. These estimates can be considered the first linking the value of agricultural products to the effect of policies at curbing coca cultivation and cocaine supply. Based on the findings, efforts to reduce coca cultivation should emphasize anti-drug strategies on production stages and trafficking with the highest value-added. This empirical evidence is crucial for strengthening legal agriculture, at least in terms of the value of agricultural production. 2.1.