%0 Journal Article %T A programa£¿£¿o matem¨¢tica positiva como instrumento de calibra£¿£¿o e prescri£¿£¿o dos modelos de oferta agr¨ªcola %A Fragoso %A Rui Manuel de Sousa %A Carvalho %A Maria Leonor da Silva %A Henriques %A Pedro Dami£¿o de Sousa %J Investiga£¿£¿o Operacional %D 2008 %I Scientific Electronic Library Online %X in this paper, calibration and prescription capacity of different types of positive mathematical programming models applied to the alentejo agricultural sector is analysed. model results are compared in the 2000 and 2004 agricultural price and subsidies scenarios, regarding optimal combination of activities. results allow concluding that positive mathematical programming is an efficient instrument on calibration of agricultural supply models, as well as on prescription of their results. %K positive mathematical programming %K agricultural supply %K calibration %K prescription. %U http://www.scielo.gpeari.mctes.pt/scielo.php?script=sci_abstract&pid=S0874-51612008000100001&lng=en&nrm=iso&tlng=en