[en] Through a regional case, this paper studies the ability of representative public institutions in Early Modern Europe to develop autonomous trade policies facing fragmented jurisdiction, as well as their efficiency and impact on markets. After applying export bans and licenses just during lean years since 1521, the Diputaci?n banned the exportation of grain in Aragon every year since 1556 to defend its jurisdiction over this matter against the Spanish monarchy and to facilitate the supply of the kingdom's population before the inflation of wheat prices. However, its management of bans protected the interest of lay nobles and big merchants. The Aragonese Parliaments regulated in 1585 and 1626 the application of these bans by the Diputaci?n in order to reduce disorder and uncertainty in the grain market. Although this institution did use these bans of cereal export often between 1585 and 1652, its decreasing political and economic power reduced their efficiency. Thus, the Diputaci?n did seek stronger cooperation of municipalities to reduce illegal cereal exports during lean years. In exchange for the monarchy's acceptance of its jurisdiction, the Diputaci?n accepted the cereal outflows of grain for the royal army free of duties, prompting their export to Catalonia during several Franco-Span- ish wars taking place between 1635 and 1697. Regular decrease of wheat prices in Aragon consolidated this trade openness during the second half of the seventeenth century, as the Diputaci?n reduced the number of bans and adapt them better to the variation of these prices. This new policy stimulated stronger efficiency and integration of grain markets in Aragon

[es] Este art?culo estudia mediante un caso regional la capacidad de las instituciones representativas en la Europa Moderna para establecer pol?ticas comerciales aut?nomas ante la fragmentaci?n jurisdiccional, valorando su eficiencia e incidencia sobre los mercados. Tras aplicar vedas y licencias de exportaci?n en a?os de carest?as desde 1521, la Diputaci?n prohibi? la exportaci?n de cereal en Arag?n desde 1556 cada a?o para defender su jurisdicci?n sobre este asunto frente a la monarqu?a hisp?nica y favorecer el suministro de la poblaci?n del reino ante la inflaci?n de los precios del trigo. Sin embargo, su gesti?n de estas prohibiciones protegi? los intereses de nobles laicos y grandes mercaderes. Las Cortes aragonesas regularon la aplicaci?n de vedas en 1585 y 1626 por la Diputaci?n para reducir el desorden y la incertidumbre en el mercado de grano. Aunque esta instituci?n sigui? utilizando estas prohibiciones a menudo desde 1585 hasta 1652, su decreciente poder pol?tico y econ?mico les rest? eficiencia. Por este motivo, busc? una mayor cooperaci?n municipal para combatir la salida de grano en a?os de carest?a. A cambio de ver reconocida su jurisdicci?n por la monarqu?a durante el siglo XVII, la Diputaci?n acept? la exportaci?n libre de impuestos de cereal destinado al ej?rcito real en tr?nsito por Arag?n, favoreciendo su salida hacia Catalu?a durante las diferentes guerras franco- espa?olas acaecidas entre 1635 y 1697. El descenso regular de los precios del trigo en Arag?n durante la segunda mitad del siglo XVII consolid? esta apertura comercial, al espaciar la Diputaci?n las prohibiciones y ajustarlas mejor a las fluctuaciones de estos precios. Esta nueva pol?tica estimul? una mayor eficiencia e integraci?n de los mercados de grano en Arag?n