On March 1, 2001, the U.S. Census Bureau issued the recommendation of the Executive Steering Committee for A.C.E. Policy (ESCAP) that the Census 2000 Redistricting Data not be adjusted based on the Accuracy and Coverage Evaluation (A.C.E.). By mid-October 2001, the Census Bureau had to recommend whether Census 2000 data should be adjusted for future uses, such as the census long form data products, post-censal population estimates, and demographic survey controls. In order to inform that decision, the ESCAP requested that further research be conducted.
Between March and September 2001, the Demographic Analysis-Population Estimates (DAPE) research project addressed the discrepancy between the demographic analysis data and the A.C.E. adjusted estimates of the population. Specifically, the research examined the historical levels of the components of population change to address the possibility that the 1990 Demographic Analysis understated the national population and assessed whether demographic analysis had not captured the full population growth between 1990 and 2000. Assumptions regarding the components of international migration (specifically, emigration, temporary migration, legal migration, and unauthorized migration) contain the largest uncertainty in the demographic analysis estimates. Therefore, evaluating the components of international migration was a critical activity in the DAPE project.
This report focuses on the evaluation of the U.S. Census Bureau's estimate of net migration between Puerto Rico and the United States in the 1980s and 1990s. Specifically, the review process evaluated and critiqued the previous estimates of net migration from Puerto Rico to the U.S. in the 1980s and created an estimate for the 1990s. To produce the estimate of net migration from Puerto Rico, the Census Bureau used an adjusted residual survival method.
Our evaluation resulted in an estimate of net migration between Puerto Rico and the U.S. of 126,465 in 1980s and 111,336 in 1990s. For both periods, migrants from Puerto Rico were more often male than female, were overwhelmingly Hispanic, and would have identified their race as being either "white" or "other". In addition, the pattern of the net migration varied by age, with flows being generally positive (toward the U.S.) for those below age 40 and negative (away from the U.S.) above age 40. Future research will focus on finding and processing administrative data that is available in the post-censal period and that will allow the estimation of both in- and out-flows of migrants between the U.S. and Puerto Rico.
This paper reports the results of research and analysis undertaken by Census Bureau Staff. It has undergone a more limited review than official Census Bureau publications. This report is released to inform interested parties of research and to encourage discussion.
The previous 1980-90 estimate: These estimates were done in a two-stage process. First, passenger traffic data for Puerto Rico were used to obtain an estimate of net international migration for Puerto Rico for the period 1980-1990. Subsequently, this estimate was adjusted using information on legal permanent international migration of foreign nationals into Puerto Rico during 1980-1990. The resultant figure, 288,163, was assumed to represent net migration from Puerto Rico to the United States for this period.
The current approach: During the process of reviewing the methods used to produce estimates and projections in the 1990s, it was determined that the passenger traffic data were too unreliable to be used for this purpose. In its place, an adjusted residual survival method was adopted and is used to the present day. Hence, this method was used by Team 10 to produce the estimates of net migration from Puerto Rico to the United States for both the 1980-1990 and 1990-2000 periods.
The adjusted residual survival method can be summarized in the following steps:
Aside from the obvious questions that could be raised about the adequacy of the chosen methods to give an accurate estimate of migration between Puerto Rico and the United States, there are two limitations of the estimates that deserve mention.
The work of Team 10 resulted in this document, two SAS program files, and two excel spreadsheets containing the estimates of migration by age, sex, race, and Hispanic Origin. The locations of each of these files are listed below. In addition, Tables A and B give a summary of the two sets of estimates:
Table A: Net migrants from Puerto Rico to the U.S. by Age and Sex: 1980s and 1990s.
Table B: Net migrants from Puerto Rico to the U.S. by Race and Hispanic Origin: 1980s and 1990s.
To summarize these tables, three points stand out: