Análise da participação da agropecuária no PIB dos EUA de 1960 a 2001

This paper analyses the evolution of agriculture’s participationin the US gross domestic product (GDP) from 1960 to 2001. Aneconometric model is run in order to identify the main variables thatdetermine this participation. From 1960 to 2001, there is a downwardtrend of agriculture’s participation in the US GDP with a break from1971 to 1973, in other words, agriculture’s participation in the US GDPdecreased from 1960 to 1970, increased from 1971 to 1973 and decreasedagain from 1973 to 2001. The 1971-1973´s break in the downwardtrend of agriculture’s participation is econometrically proved. Datasetorganized in graphs show grain and meat production steadily enlargedfrom 1970 to 2001, what is closely related to the productivity increaseand federal grants to agriculture, despite the ratio of received/paidprices decreased during this 31 years. An accounting model is presentedto show the main variables that determine agriculture’s participationin a country’s GDP and an econometric model is derived from thisaccounting model. Running this econometric model with 1973-2001´sUS dataset, the following variables are the most important to determinethe participation of agriculture in the US GDP: received/paid pricesratio, lagged value of agriculture’s participation in the GDP, and totalfactor productivity of the agriculture.