Antimicrobials have been used in human medicine and in livestock production for more than 60 years, improving human and animal health but also fostering the emergence and spread of antimicrobial resistant pathogens worldwide. This report focuses on the specific issue of the economic value of antimicrobial growth promoters (AGPs) to producers and consumers. After estimating orders of magnitude of current antimicrobial consumption in livestock globally, the report investigates the potential effects of restricting AGPs on livestock production globally. The growth response to AGPs appears to be small in optimised production systems, suggesting that the economic impacts of a ban on AGPs could be limited in high-income industrialized countries but potentially higher in lower income countries with less developed hygiene and production practices. With no major changes in policy, global consumption of antimicrobials in food-producing animals is projected to rise by two-thirds by 2030, with the majority of that increase occurring in emerging economies where the demand for livestock products, especially poultry, is growing fastest.