Spanish Abstract: El principio general de la buena fe irradia el ordenamiento juridico incluso en materia contractual, en este caso, imponiendo una regla de conducta leal, honesta y diligente, lo cual obliga a todo aquel que realice actos encaminados a producir efectos juridicos. En este orden, los juristas suelen acudir a la buena fe a fin de justificar la regla aplicable a una situacion concreta, incluso, respecto de la atribucion del riesgo por perdida de la cosa debida en el contrato de compraventa. Sin embargo, en codificaciones como la colombiana subsisten simultaneamente dos reglas contrarias: la periculum est emptoris, la cual suele aplicarse en materia civil, y la periculum venditoris, de mayor aplicacion en materia comercial. Ante esta dicotomia de reglas, y amparado en el mismo principio de buena fe, la doctrina ha tendido a favorecer la regla periculum est emptoris. En este contexto, el presente escrito pretende partir del analisis economico del derecho a fin de evaluar los resultados que cada una de estas normas produce y determinar cual es mas eficiente, ello, a fin de improbar o ratificar el argumento derivado de la buena fe English Abstract: The general principle of good faith is a legal principle that pervades the entire legal system, including contract law. In this area of law, good faith obliges the parties to behave in a loyal, honest and diligent manner. In this order, jurists often resort to good faith in order to justify the rule applicable to some contractual contingencies, including which party assumes the risk of loss of what is still owed in the contract of sale. However, in codified jurisdictions such as Colombian law, two contrary rules subsist simultaneously: the periculum est emptoris rule, which is usually applied in civil law, and the periculum venditoris rule, which is applied in commercial law. Given this dichotomy of rules, the legal doctrine usually states that the principle of good faith is consistent with the periculum est emptoris rule. In this context, this paper departs from the economic analysis of law in order to evaluate the results that each of these two rules produces and determine which one is more efficient and with the purpose of refuting or ratifying the argument defended by the legal doctrine.