Understanding the importance of the dynamic entry process in the Canadian economy involves measuring size of entry. The main purpose of this paper is to summarize the information we have on the amount of entry in Canada. The paper also fulfils another purpose. Some studies have focused on cross-country comparisons (Geroski and Schwalbach 1991; OECD 2001). Interpretation of the results of these studies is difficult unless methodological issues regarding how entry is measured are addressed. Without an understanding of the extent to which different databases produce different results, international comparisons are difficult to evaluate. Cross-country comparisons that are derived from extremely different data sources may be misleading because of the lack of comparability. Since there is more than one reliable database that can be used to estimate entry in Canada, this paper asks how measured entry rates vary across different Canadian databases. By examining the difference in entry rates produced by these databases, we provide an estimate of the range or confidence interval that should be used in evaluating whether there are real differences in measured entry rates across countries. We also offer guidance as to the questions that should be asked about the databases used by researchers who conduct international studies. Finally, we make suggestions as to areas of comparison on which international studies should focus.