Factors motivating the decision to file an antidumping petition are analyzed with data from 1976-1988 for the US chemical industry. The incidence of antidumping filings is related to disaggregated levels of and changes in microeconomic variables in a count model framework. Import penetration, number of employees, price-cost margins, the chemical production index, and dumping margins all significantly influence the filing decision, while average wages, the capital-to-shipments ratio and the new capital expenditures-to-shipments ratio do not. There is also evidence that antidumping filings increased significantly following implementation of the Trade Agreements Act of 1979.