For the United States and selected states, this study generates indicators of the net census coverage error of Hispanics age 0 to 9 years in the 1990 census of population. Using annual Hispanic births (1980-1990), estimates of net Hispanic immigration, and estimated mortality, the "demographic accounting equation" is used to calculate the residual (difference) between the survived intercensal Hispanic population cohort age 0 to 9 years and the enumerated 1990 census Hispanic population that age. This residual is an indicator of the net coverage error for young Hispanics. Apart from the finding on Hispanic census undercount, the analytic study provides two additional observations, namely: (1) that the annual number of Hispanic births based only on origin of mother is inconsistent with the census- enumerated Hispanic origin universe (which includes children with Hispanic-only fathers as well as Hispanic mothers) and (2) that in the 1990 census-editing of item nonresponse, the characteristic "Hispanic origin" may have been over-allocated in the census 100-percent questionnaires relative to the allocation level used for the sample questionnaires.
The views expressed are attributable to the author and do not necessarily reflect the views of the U. S. Bureau of the Census.
If you have any questions concerning this report, please e-mail a message to firstname.lastname@example.org. Include the name of this report and author in the body of the message.
Since 1960, the U.S. Bureau of the Census has evaluated the accuracy of its decennial census population coverage by age, sex, and race. In particular, for the 1980 and 1990 censuses, the Bureau used a survey method and an analytical method to measure the completeness of census coverage; both methods have strengths and weaknesses, ultimately complementing each other in estimating the accuracy of the decennial census population count. The survey method used was the Post-Enumeration Survey (PES) (Hogan, 1993), which estimated that the 1990 census had undercounted about 1.6 percent of the total population and about 5.0 percent of the Hispanic population; the analytical method used was the so-called Method of Demographic Analysis (DA) (Robinson et al., 1993), which estimated that the 1990 census undercounted the total U.S. population by 1.8 percent.
In general, the DA method estimated the 1990 census net coverage error by age, sex, and race mainly by reconstructing the population at census date from components of population change, namely: births, deaths, and immigrants. This estimated "reconstructed" population is then compared to the enumerated census population (by age, sex, etc.) and the differences between the two populations attributed to census coverage error.
Previous studies show that we cannot use the DA method to estimate the 1990 census Hispanic population coverage because we lack recorded Hispanic vital registration data (i.e. births and deaths) for past decades (Fernandez, 1991a, 1991b). But for the 1980-1990 decade, we can estimate the number of Hispanic births and deaths, and the volume of Hispanic immigration quite reliably. We then apply to these data the "demographic accounting equation", generate an independent estimate of the Hispanic population age 0 to 9 years in 1990, and subsequently measure its census coverage error by the method of demographic analysis.
In brief, in this study we reproduce the expected young Hispanic population (i.e. age 0 to 9 years) at the 1990 census date. This expected population is created by two simple events: (1) the 1980 to 1990 Hispanic births, survived according to an appropriate mortality scheme, and (2) the number of Hispanic children age 0 to 9 years immigrating to the U.S. during the 1980-1990 intercensal interval. Fortunately, we can get (or closely estimate) the data for these events and subsequently construct the Hispanic population cohort age 0 to 9 years at the census date. We then estimate its census coverage by calculating the difference between the expected Hispanic cohort age 0 to 9 years and the actual census count of that same Hispanic population age group.
Although from the above data we cannot measure census coverage for the Hispanic population of all ages enumerated in the census, we can at least do so for Hispanics under 10 years of age, both for the entire U.S. and for States which have consistently recorded Hispanic births since 1980.
Most States in the U.S. now record Hispanic origin births and deaths in their vital registration systems, but this was not so until recently. In fact, in 1980 only twenty-two States identified Hispanic , and within this group we immediately recognize 10 States that have had consistently high concentrations of Hispanic persons. We have labelled these States the "Hispanic States", and they include: California; Texas; New York; Illinois; Florida; Arizona; New Jersey; New Mexico; Colorado; and Hawaii. The remaining twelve States we call the "Non-Hispanic States", they are: Ohio; Utah; Nevada; Kansas; Indiana; Georgia; Nebraska; Wyoming; Arkansas; Mississippi; Maine: and North Dakota. This artificial grouping of our 22 States into "Hispanic" and "Non-Hispanic" is important because it will help reenforce our conclusions about the quality of the data used to describe the Hispanic population and the level of coverage of the 1990 census enumeration of young Hispanics.
From the National Center for Health Statistics (NCHS), we obtained Hispanic birth data for each of the above 22 States for the years 1980 through 1990. These births represent calendar-year births; undifferentiated by sex; and uncorrected for birth underregistration. We therefore modified the recorded births by: (1) adjusting from calendar year to "census" year (i.e. years ending on 3/31); (2) differentiating by sex; (3) increasing the Hispanic births by proportionally allocating births of unknown origin, and (4) correcting for underregistration of births.
Specifically, for each of the 22 States, the "calendar year" Hispanic births were adjusted to "census" year by using quarter-year seasonality factors based on Hispanic births occurring in calendar year 1985. The births were then differentiated by sex using the general assumption of 105 male Hispanic births per every 100 Hispanic female births.1/(FOOTNOTES NOT AVAILABLE ELECTRONICALLY) Subsequently, for each State, the annual births were increased by a small factor based on the number of total State births with origin-not- reported. Finally, the births were corrected for underregistration using relatively small factors derived by combining results from the U.S. birth-registration test of 1964 to 1968 and from Bureau staff research regarding the annual underregistration of births by State. Generally, we assumed that the completeness of registration of Hispanic births was about 98.7 percent accurate, and that this applied equally to each of the 22 States. 2/
To get Hispanic births for the entire U.S., we also had to estimate these births for the non-reporting States. This was done somewhat roughly by calculating a factor based on the number of children-ever-born to women of child-bearing age in the 22 reporting-States and applying this factor to the residual cluster of non- reporting States. This action was not critical for our final results, however, because only about 5 percent of the Nation's Hispanics live outside the 22 States reporting Hispanic births since 1980.
In the study of U.S. Hispanic growth and change, the mortality component is not as critical as either fertility or migration. Generally, we assumed that in the 1980-1990 intercensal period the 10-year survival rates of Hispanic births were best exemplified by the rates of the 1979-1981 life table survival rates of the U.S. White population. We also assumed that this same mortality applied in each of the 22 States of our study.3/ Overall, this mortality effect reduced the total number of intercensal Hispanic births by only about 1.3 percent (Table 1).
Besides intercensal Hispanic births, we also needed to estimate the number of young Hispanic immigrants age 0 to 9 years entering the U.S. during the 1980- 1990 period. This migration process was subdivided into its components, namely: (1) Legal Immigration; (2) Refugee immigration; (3) Net Puerto Rican migration; (4) Net illegal (i.e. undocumented) migration; and (5) Legal emigration. These data came from two distinct sources, namely: national level immigration data compiled by the Census Bureau's estimation and projections programs (adjusted from fiscal to census year), and data furnished by the Immigration and Naturalization Service (INS) on the annual number of immigrants entering the U.S. by reported "intended" State of residence.
Legal alien immigration. - For this study, we allocated legal Hispanic international immigrants to the 22 States according to the INS distribution of 1990 immigrants to the U.S. by specific country of origin and State of intended residence. - The "sending" Hispanic countries included: Colombia, Cuba, Dominican Republic, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, and Peru. - We assumed that the percent distribution by State of these 1990 immigrants age 0 to 4 and 5 to 9 years, by sex, was the same for all Hispanic immigrants for each year of the intercensal period (i.e. 1980-1990). (Table 1).
Refugees. - Most Hispanic refugees admitted annually to the U.S. are Cuban-born persons, so our refugee data referred only to Cuban refugees. Future analysis should include refugee-data from all countries. Since refugee data were unavailable by State, we distributed the annual number of Cuban refugees to each of the 22 States according to their reported State-of-intended-residence at time of entry. This resulted in apportioning 80-percent of all Cuban refugees to Florida for each year of the 1980-'90 intercensal period (Table 1).
Net Puerto Rican Migration. - Although we had net migration data from Puerto Rico for each year of the 1980-1990 intercensal period, this data was only available for the U.S. as a whole. Therefore, we apportioned this Puerto Rican flow to each of the 22 States for each intercensal year according to the 1990 census distribution of enumerated Puerto Rican origin persons by State. This resulted in an allocation of 39 percent of annual Puerto Rican migration to New York; 12 percent to New Jersey; 5 percent to Illinois; 5 percent to California, etc. (Table 1).
Illegal Aliens. - To accurately estimate the Hispanic population age 0 to 9 years at census date, we had to make allowance for illegal Hispanic immigration during the 1980-1990 decade. We estimated about 150,000 net Hispanic illegal immigrants per year - from an estimate of about 200,000 net annual illegal aliens.4/ The number of Hispanic illegal aliens age 0 to 9 were calculated by using the same proportion of Hispanic origin persons of that age to total Hispanics enumerated in the census. These persons were then allocated appropriately to each of the 22 States in the same proportion as the distribution of illegal aliens counted in the 1980 census by State (Passel,et al., 1984). In general, about 88 percent of young- Hispanic illegal aliens entering during the 1980-1990 decade were allotted to the 22 States in our study (e.g. with California receiving about 50 percent of them). (Table 1).
Legal Emigration. - Emigration, or the outflow of the U.S. resident population, is estimated by the Bureau at about 160,000 persons per year, and from this number we estimated that for the 1980-1990 intercensal period the number of Hispanics age 0 to 9 years, by sex, leaving the U.S. every year was about 1,800 persons.5/ We then cumulated these yearly cohorts to get the overall Hispanic emigrant population age 0 to 9 years, by sex, during the 1980-1990 period. Subsequently, we apportioned these persons by State according to the distribution of reported "intended" State of residence given to the INS by legal Hispanic immigrants (Table 1).
To estimate census coverage at the national level by the Residual method, the migration component need only refer to international migration. But to estimate coverage at State levels, as we do in the present study, we need to consider also the effect of internal migration during the intercensal period. For some of the States in our study, the young Hispanic internal migration factor is important and can alter somewhat our census coverage results. In the Appendix, we elaborate on this migration factor and adjust our final results accordingly.
As noted, we have estimated the coverage of young Hispanics by the direct application of the demographic "accounting" equation to: (1) recorded Hispanic births, (2) estimated Hispanic deaths, and (3) recorded and estimated immigration data. We used three approaches, based on assumptions about these data, to generate three successive estimates regarding the 1990 census coverage of young Hispanics. In the first approach, we applied the demographic "accounting" equation (i.e. births minus deaths plus net immigration) to the given data. In the second approach, we increased the number of estimated intercensal Hispanic births used. And in the third approach, we used the increased number of Hispanic births, but slightly lowered the 1990 census allocation counts of young Hispanics by using long- form questionnaire (17 percent sample census) allocation rates instead of the short- form (100 percent census) allocation rates. For each of the three different approaches, the immigration figures were maintained the same. Later, our third set of coverage results were modified to account for the effect of internal migration (see Appendix and tables).
The survived intercensal Hispanic births (classified as Hispanic by origin of mother) plus the calculated net intercensal immigration of Hispanics age 0 to 9 years during the 1980-1990 decade yielded the cohorts age 0 to 4 years and 5 to 9 years at the 1990 census date. Comparing these cohorts with the actual 1990 census counts of Hispanics in those age groups showed that, in most of the 22 States of our study, the estimated young Hispanic groups were substantially smaller than the corresponding census counts of those groups, indicating that the 1990 census had substantially overcounted Hispanics age 0 to 9 years in most of the States !!! (see Table 1)
Although some States did show census undercounts of young Hispanics, these undercounts occurred mostly in typically "Hispanic" States (i.e. California: 1-percent undercount; New Jersey, 12-percent; and Texas, 2-percent). But most of the States - in this first round of results - showed a census overcount of young Hispanics. For example, Arkansas showed a 45 percent "overcount" of young Hispanics; Georgia, 74 percent; Indiana, 72 percent; Mississippi, 95 percent; and Nevada, 50 percent. Overall, the census counts showed an average of 4 percent overcount of Hispanics age 0 to 9 years in the U.S.
Intuitively we believe it improbable that the 1990 census could have overcounted young Hispanics - especially to the degree shown for the non-Hispanic States noted above. In fact, the Post Enumeration Survey (PES) showed an undercount of Hispanics in all States! Specifically, the PES showed that - on average - about 5 percent of Hispanic origin persons in the U.S. were missed in the census, and that for the 22 States of our study, there was an undercount of Hispanics which ranged between 3 to 7 percent for those States. Interestingly, and contrary to our first set of results, the PES showed that the 1990 census Hispanic undercount levels were particularly severe in the "Non-Hispanic" States of our study.
This disparity between our first set of coverage results and the PES strongly suggested that something was amiss in our coverage estimation scheme of young Hispanics. Could the 1990 census truly have overcounted young Hispanics in most of the 22 States of our study? Or are the overcounts simply aberrant results produced by underestimating Hispanic births in the implementation of our residual method? Are the census counts of Hispanic origin persons inflated by excessive 100 percent Hispanic-question allocation rates? Are there other factors operating here? The second and third round of results, shown below, will help answer some of these questions.
Some comments on the first round of results. - Since results show significant improbable overcounts of Hispanics in most "Non-Hispanic" States, and overcounts and some small undercounts in the "Hispanic" States, it is very likely we are underestimating our State intercensal Hispanic births and/or immigrants. If so, we should question our sources and our methods when using these items.
In our first set of results, the census "overcounts" of young Hispanics underscores the incomparability that sometimes occurs when two different statistical-collecting systems are used to collect data and produce results from a single conventional population. In this case: vital registration and the decennial census undoubtedly differently classify the same item: Hispanic origin. For instance, in the vital registration system of States births are classified as Hispanic - or other origin - according to the origin of the mother only; in the 1990 census, however, respondents are asked to report whether or not they are of Hispanic origin, and since the question elicits a subjective response, some children were probably reported as Hispanic solely because of the Hispanic origin of the father. Therefore, the classification of a person as Hispanic origin in the vital registration system is presently not equivalent to identification as Hispanic in our decennial census, and we must tread cautiously when interpreting the analytical results derived from combining data on the same characteristic (in this case: Hispanic origin) but identified in different statistical collecting-systems.
Theoretically, the resulting Hispanic cohort created from surviving intercensal Hispanic births and adding immigrants may not be comparable to the equivalent Hispanic cohort enumerated in the census, for example, if the intercensal births - and to a lesser extent: immigrants - are understated during the decade, the estimated "expected" Hispanic population age 0 to 9 years at census date would be expectedly smaller than the census-enumerated Hispanic population of that age group. Therefore, to provide for better comparability, we increased the registered Hispanic births for each individual State by 13.9 percent - which is an estimate of the proportion of Hispanic births by origin of father when the origin of the mother is non-Hispanic.6/ ( Table 2).
The significant aspect, then, of our second set of results was that we classified Hispanic births according to Hispanic origin of mother plus Hispanic origin of father (when the mother's origin was non-Hispanic).7/ The outcome was that the increased Hispanic births substantially reduced the overcount level in most of the "Non-Hispanic" States of our study and concurrently increased the undercount rates in the so-called "Hispanic" States. The overall U.S. net census coverage of young Hispanics in the 1990 census was now estimated as an undercount of about 8 percent instead of as an overcount of 4 percent estimated by our first approach (see Table 3), and the individual States poignantly reflected this overall transformation. For example: Arizona, instead of an overcount of Hispanics 0 to 9 years, now indicated an undercount of this group of about 2 percent. Colorado now showed a 1 percent undercount; Illinois, 11 percent; New Mexico, 6 percent. Evidently, the increase in the number of Hispanic births (i.e. now based on origin of mother or father) produced indicators of net 1990 census coverage of young Hispanics which were much more reasonable than those derived in the first set of results in which Hispanic births were based solely on origin of mother.
In summary, our second set of coverage results are more plausible than the first set (Table 6). Increasing the Hispanic births made our estimated young Hispanic population base more comparable to that of the census, in which children may be identified as Hispanic according to origin of mother or father. This second set of results underscores the importance of using comparable data in different statistical collecting systems.
Although increasing the number of intercensal Hispanic births gave more realistic census coverage rates of young Hispanics, for a few States the rates still appear unreasonable. For example, in the second set of results some "Non- Hispanic" States still showed large overcounts and some "Hispanic" States still trivially small undercounts. Therefore, either we were still understating the processes of intercensal change (e.g. births and immigration) for Hispanics age 0 to 9 years during the 1980-1990 intercensal period, or the 1990 census counts of that age group were in some way artificially overinflated, possibly through some aspect of census-questionnaire processing.
During the 1990 decennial census, questions that were left incomplete, had inconsistent or unreasonable responses, or simply were left entirely unanswered, had responses "imputed" by computer. These "imputed" responses were called imputations or allocations. The imputation rate (i.e. allocation rate) for the 1990 census Hispanic origin question of persons age 0 to 9 years was 7.2 percent. Generally, this was much higher than for other short-form census questions. In the short-form questionnaire, over three-quarters of a million persons age 0 to 9 years were allocated as "Hispanic origin"; but in the 1990 census long-form (i.e. sample census) questionnaires, about half that number of persons were allocated as Hispanic.
We suspect that the number of response-imputations of "Hispanic origin" inserted in the short-form questionnaires during 1990 census-processing was excessive, and generally we believe that the greater number of questions and, therefore responses available for editing the census long-from questionnaire offers a more correct selection of response-allocations than the short-form questionnaire. Hence, the number of allocations of "Hispanic" origin inserted in the long-form questionnaires should be more credible than the number from the short-form questionnaires. Since in our study we compared the residual-method estimates of young-Hispanics with the 1990 census 100 percent counts of these persons, the noticeable census excess (i.e. overcount) for certain States could have been caused - at least partly - by an over-allocation of young-Hispanic origin persons in the census. (Table 4)
Therefore, in an attempt to get more accurate and realistic estimates of young Hispanic census coverage, we derived yet a third set of results by adjusting the 1990 census young Hispanic counts downward by using the long-form allocation rates of "Hispanic origin" responses instead of the "inflated" short-form allocation rates used to produce the 1990 census (100-percent) Hispanic counts. (Table 5). The rationale for our action was to try again to legitimately reduce the inexplicably high "overcounts" of Hispanics in the NonHispanic States of our study. At this point, we should note that in these States, where the concept of Hispanic origin is not as well recognized as in other areas, we would expect more non-responses in the Hispanic origin question and thus more erroneous allocations ("false positives) of "Hispanic origin" than in other States. In any case, we believe that in most States the imputation rates of "Hispanic origin", based on long-form questionnaire responses were probably more correct than the rates based on short form questionnaires responses.
For our third and final set of results, therefore, we used: (1) the same intercensal immigration factor as in the other two sets of results (Table 5); (2) Hispanic births by origin of father (mother non-Hispanic) in addition to Hispanic births by origin of mother; and (3) census long-form allocation rates instead of short- form allocation rates. With these modifications, this final set of results generated a more plausible (higher) indication of undercount of young Hispanics in the "Hispanic" States and substantially lower overcounts in the "Non-Hispanic" States. For the entire U.S., the net 1990 census undercount rate of Hispanics age 0 to 9 years then became 11.2 percent, or over half-a-million persons (Table 5).
The census coverage errors for young Hispanics now seemed more plausible because they showed normally expected undercounts in most of the heavily "Hispanic" States and somewhat reduced overcounts in the "NonHispanic" States. Prior to simple adjustment due to internal migration (shown in the Appendix), in this third set of results "Hispanic" States such as New York and New Jersey showed more than a 25-percent undercount of young Hispanic children;8/ Texas, Illinois, and California about 15 percent undercount each; Hawaii, over 10 percent; New Mexico, 8 percent; Colorado, 4 percent; Arizona, 3 percent; and Florida, 1 percent.9/ Overall, the implied young Hispanic net census undercount for the combined "Hispanic" States of our study was 15.5 percent.
Most of the "Non-Hispanic" States, however, continued to show overcounts of young Hispanics in the census, and for these States combined the net overcount rate reached 18.7 percent. Particularly high levels were noted for Mississippi, which showed an overcount of over 55 percent followed by Georgia, over 45 percent; Maine, over 40 percent; Nevada and Kansas over 25 percent, etc. (Figure 1). These "overcounts" are still rationally unexplainable. Could they be caused, at least in part, by mixing two different identification modes for Hispanics in our estimating-scheme, namely: administrative data (such as: the vital registration of Hispanic births, etc.) and the decennial census responses to the subjective question used to identify persons as: "Hispanic" origin?
As noted previously, another factor to consider in determining the magnitude of the coverage rates is the internal migration effect. However, for the "NonHispanic" States, this effect does not reduce the overcounts significantly.
The original goal of this study was to analytically determine the net census coverage error of Hispanics age 0 to 9 years enumerated in the 1990 census. To do this, we survived the 1980 to 1990 occurring Hispanic births and calculated the net Hispanic immigration during that period. To these cohorts we applied the "demographic accounting equation" to calculate the residual between the resulting survived intercensal Hispanic cohort age 0 to 9 years and the enumerated 1990 census population of that age. This residual ostensibly represented an estimate of net 1990 census coverage error for Hispanics age 0 to 9 years. At first, the unreasonable estimates of overcoverage from our first set of results persuaded us to use: (1) Hispanic births also based on Hispanic origin of father, and (2) 1990 census sample-questionnaire allocations of "Hispanic origin" instead of the 100 percent allocations. These refinements narrowed the unreasonable gap between each of the estimates and the census counts and improved our final net census coverage rates. In general, the "high" undercount rates shown for some "Hispanic" States in our third set of results (see Table 6) may not be unreasonable. But the overcounts in the "Non-Hispanic" States, although reduced somewhat, are still highly improbable. In any case, we can still make some very positive inferences from this study. (Figure 2).
Firstly, we must stress that the undercount levels shown for the "Hispanic" States are simply plausible "indicators" of net census coverage error of young Hispanics rather than direct "estimates" of coverage. Still, these "indicators" can add to our understanding of the 1990 census coverage estimates of the overall U.S. Hispanic population and lead the way to developing analytic measures of coverage in the 2000 census.
Secondly, it appears that the intercensal Hispanic births tabulated by the National Center for Health Statistics and used by the Census Bureau in its estimates and projections programs are understated relative to their use with the reporting of Hispanic origin in the census. We believe it imperative that, to improve the comparability of Hispanic origin data collected by these two agencies, Hispanic births be classified according to origin of father as well as by origin of mother. Our second set of results alone shows the enormous impact that this extension would have in estimating overall census Hispanic population coverage.
Thirdly, in an effort to reduce the unexpected high census overcounts of young Hispanics in most of the "NonHispanic" States, we used the sample-census (long-form) questionnaire allocation rates of "Hispanic" origin. As noted above, the short-form rates were about double the long-form rates and our contention is that the former probably overinflated the Hispanic origin counts in some States; /10 although this overinflation factor was probably more than compensated for, at least in the "Hispanic" States, by the anticipated census undercount of Hispanic persons.
In general, then, for selected States (particularly those with "large" Hispanic populations) we believe we have derived reasonable indicators of 1990 census undercount levels of Hispanic origin persons age 0 to 9 years. Furthermore, a by- product from this study - which emerges conspicuously - is the realization that we should examine closely the appropriateness of the annual Hispanic fertility and migration rates used in the Census Bureau's estimates and projections programs, and in the analysis and estimation of the net census coverage error of our decennial censuses./11
Fernandez, Edward (1991a) "Measurement of Hispanic Undercount by Demographic Analysis: Problems and Possible Solutions." Paper presented at the Population Assoc. of America meeting in Washington, D.C. March 21-23, 1991.
Fernandez, Edward (1991b) "Can We Measure the 1990 Census Coverage of Hispanics by Demographic Analysis?" Paper presented at the Southern Demographic Assoc. meeting in Jacksonville, Fl. October 10-12, 1991.
Hogan, Howard (1990) "The 1990 Post-Enumeration Survey: An Overview." Paper presented at the Population Assoc. of America meeting in Toronto, Canada, May, 1990.
Passel, Jeffrey et al. (1984) "Geographic Distribution of Undocumented Immigrants: Estimates of Undocumented Aliens Counted in the 1980 Census By State." International Migration Review 18 (Fall 1984: 642-671).
Robinson, J.Gregory et al (1990) "Evaluating the Quality of Estimates of Coverage Based on Demographic Analysis." Paper presented at the Population Assoc. of America meeting in Toronto, Canada, May 1990.
National Center for Health Statistics (1989) Vital Statistics of the United States, 1987, Vol. 1, Natality. DHHS Pub. No. (PHS) 89-1100. Public Health Service, Washington. U.S, Government Printing Office, 1989.
|Origin of Father||Origin of Mother||Total|
The data in the table clearly show the impact of adding births as Hispanic because of Hispanic origin of father to births by Hispanic origin of mother.
As shown in the text, to derive our "indicators" of 1990 census coverage of young Hispanics we measured the processes of population change of this population during the 1980 to 1990 intercensal period to generate, by the residual method, our three sets of coverage estimates. However, we did not include the internal migration (i.e. State-to-State migration) factor because of the difficulty of getting information on this type migration for Hispanics age 0 to 9 years. Although for some States the effect of this migration may not be trivial in determining census coverage, its inclusion will probably not alter our results substantially nor our inferences regarding 1990 census young Hispanic population coverage by State.
Nevertheless, we have calculated the internal migration factors for the twenty-two States of our study by using 1990 census 5-year migration data for the total population. Assuming that the internal migration of Hispanics age 0 to 9 years is equivalent to that of the total population, we applied this factor (Table A-1) to our third and final set of census coverage results. (Table A-2). Almost without exception, the inclusion of the internal migration factor has had a salutary effect on our coverage results. For example, those States which showed inordinately high undercount rates of young Hispanics, such as New York and New Jersey - as well as other "Hispanic" States - now show slightly less (although still significant) census undercoverage. For the "Non-Hispanic" States, the internal migration effects are less definitive, but generally make the coverage results more plausible.
Future inquiry about Hispanic population coverage by State or by smaller geographical area(s) should consider the period effect of internal migration. We plan to obtain tabulations from the 1990 census showing 5 year internal migration data for Hispanic persons age 0 to 9 years, and include this information in our analysis of the coverage error of young Hispanics. Since the Hispanic population is composed of several large singular groups with some markedly different characteristics, dissimilar residence concentrations, and distinctive migration patterns, we should include this migration factor in any study using the residual method to estimate census Hispanic coverage error.
|Selected States||Percent estimate of net census coverage error (third set)||Estimated Percent Internal migration rate||Adjusted net census coverage error|