Relationships between cotton export sales and export shipments are examined, and a quarter-specific lag structure is estimated. Two econometric systems are estimated, one employing export shipments and the other using export sales. Results indicate that sales are more sensitive to changes in economic variables than shipments and that stocks net of outstanding export sales are more responsive to price and interest rate changes than gross stocks. Sales and shipments are different variables and cannot substitute for one another in econometric modelling. Use of export sales data should be considered in estimation of export demand and stock demand parameters.