Changes in the welfare effects of recombinant bovine somatotropin from 1996 to 2002 in the USA

From 1996 to 2002, the percentage of dairy cows treated with recombinant bovine somatotopin (rBST) in the USA more than doubled, while the price of milk fell considerably. The benefits of the increased milk production to consumers, and to the economy as a whole, were greater in 2002 than in 1996. The economic surplus of producers who did not use rBST was more negatively affected by rBST in 2002 than in 1996. Dairy producers who used rBST enjoyed an increased economic surplus from the increased milk production associated with rBST during 1996. During 2002, the impact on producer surplus for users of rBST was not significantly different from zero.