A structural model of the spring onion economy is developed to analyze forces affecting the onion-producing sector in Texas. Spring onion prices in Texas are influenced by own shipments, shipments from storage stocks, and variety. Texas's decline in market share is largely the result of expanded late summer (storage) onion production. A decline in the U.S. real tariff and a weakening of the real exchange rate (pesos/$) encouraged onion imports from Mexico during the study period. However, this impact was offset by the imposition of quality standards in 1980 and the growth in domestic late summer onion production. Study period results did not support the recent contention of Texas producers that onion imports from Mexico are unfavorably affecting prices received.