The share of raw milk meeting fluid quality (Grade A) standards in the United States rose steadily through the latter half of the twentieth century, but a shrinking portion of that was used in fluid products. Grade A milk exceeds the quality standards for the manufactured products for which it has been increasingly used. We present an econometric model that exploits regional and temporal variation in policy implementation to identify the effect of marketing orders on the Grade A share of milk. Results support the hypothesis that marketing orders significantly encouraged the growth in the Grade A share of milk. Copyright 2007, Oxford University Press.