Obtaining estimates of pesticides productivity is an economic response to the growing public concern about the steady increase of pesticide use in the United States. This type of research indicates the cost of limiting pesticide use in terms of foregone output. Pervious empirical studies give a "snap-shot", or "average", look at pesticide productivity. This research effort employs a random coefficient model to determine the trend of the marginal value product of pesticides in agriculture in the United States. Results show a distinct downward trend in two states, Iowa and Texas. California, however, shows no evidence of a downward trend.