When the results of a new census become available, there may be a tendency to immediately move to the analysis and then use the results as the basis for new yearly estimates as well as longer-term projections of the population. This paper will discuss several reasons why it is a good idea to pause and reflect before abandoning estimates and projections based on an earlier census to be sure that all the lessons learned from the comparison to the new census can be appreciated. We will explore several processes where the comparison of census and population estimates or projections can be useful and also will look at examples of these processes and pose some questions about further research. Our goal is to increase discussion of lessons learned by comparing census results to population estimates and projections.

Paper presented at the 21th Population Census Conference, Analysis of the 2000 Round of Censuses, Kyoto, Japan, 19 - 21 November 2003.