01545naa a2200265 a 450000100080000000500110000800800410001902200140006010000170007424500930009126000090018430000190019349000110021250000410022352007970026465000170106165300300107865300270110865300150113570000290115070000220117970000160120170000280121777300340124516573622010-07-08       2009    bl uuuu     u00u1 u    #d  a0254-53301 aGOMES, E. G.  aEfficiency and sustainability assessment for a group of farmers in the Brazilian Amazon.  c2009  a167-181 v. 169  vv. 169  a0254-5330 (Print) 1572-9338 (Online)  aThe aim of this paper is to use DEA models to evaluate sustainability in agriculture. Several variables are taken into account and the resulting efficiency is measured by comparison. The performance of family farms is analysed here (variables: farmed area, work force, and production). As agricultural sustainability depends on the maintenance of systems of production for long periods of time, the models were run for the years of 1986 and 2002. Tiered DEA models were used to group farmers in sustainability categories. Non-parametric regression models were used to identify the factors affecting the efficiency measurements. All the results indicate that the majority of the farmers increased their efficiency along the time. These improvements may support the existence of sustainability.  afamily farms  aData envelopment analysis  aIso - efficiency tiers  aRegression1 aMELLO, J. C. C. B. S. de1 aSOUZA, G. da S. e1 aMEZA, L. A.1 aMANGABEIRA, J. A. de C.  tAnnals of Operations Research