The International Price Program uses an establishment survey in which monthly price data is collected for goods imported into the U.S. or exported from the U.S. This paper discusses the model developed to describe the sample loss at each stage of the survey process from frame preparation through index estimation. During the survey process business establishments are selected and refined. Within selected establishments, general product categories are sampled for initiation. Unique items are then selected within each general category during an initiation process and the selected items are repriced each month until they are phased out of the survey. Broad categories of sample response are described and detailed reasons for each category are explored. Actual loss rates for recent importer and exporter samples are also given.