Summary: Traditionally, the Census Bureau has counted the American population by compiling an address list of households, mailing out questionnaires to those addresses, and hiring temporary census takers to follow up with nonresponding households. For the 2000 census, the Census Bureau had planned to supplement these traditional methods with statistical estimation. Congress, however, questioned the constitutionality of using statistical sampling, and the Supreme Court ruled this year that the Bureau cannot use statistical sampling to determine the population count used to apportion the House of Representatives. As recently as August 1997, the Bureau estimated that without sampling, the cost of the census would rise by as much as $800 million and would be less accurate than the 1990 census. Following the Supreme Court's decision, the Bureau sought to increase its fiscal year 2000 budget by more than $1.7 billion. This report (1) analyzes the key changes in assumptions resulting in the requested increase of $1.7 billion; (2) provides details on the components of this increase and which changes, according to the Bureau, are related and which are unrelated to the inability to use statistical sampling; and (3) describes the process the Bureau used to develop the increase in its original budget request for fiscal year 2000 and the amended budget request.