3
Demographic Trends

Recruitment to the armed forces is constrained by the broader social environment in which young people grow up. A key part of that environment is the demography of the youth population, which changes substantially over time as a result of long-term trends in fertility and the activities that structure the lives of young people. Demographic processes constrain armed forces recruitment in a number of ways. First, secular trends (i.e., trends over time) in fertility determine the sizes of future cohorts of youth and thus affect the ease with which recruiting targets can be met. The absolute sizes of cohorts of women of childbearing age and the rates at which those women bear children determine the numbers of children in each year. These numbers are also augmented by immigration of children and teenagers and depleted by mortality and emigration of these groups, but these effects on the youth population are small relative to fertility.

Second, trends and levels of differential fertility affect each youth cohorts’ average propensity to enlist in the armed forces. The family environments in which young persons are raised affect their propensities to enlist or to engage in other activities that may complement or substitute for military service. These environments are affected by the socioeconomic characteristics of families, their size and structure, and other aspects of parents’ social backgrounds. Adults from different kinds of families bear children at different rates, with these differentials often varying over time. Other things being equal, therefore, fluctuations in these patterns of differential fertility will affect the average enlistment propensities of later cohorts of offspring when they reach the appropriate age for military service.



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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment 3 Demographic Trends Recruitment to the armed forces is constrained by the broader social environment in which young people grow up. A key part of that environment is the demography of the youth population, which changes substantially over time as a result of long-term trends in fertility and the activities that structure the lives of young people. Demographic processes constrain armed forces recruitment in a number of ways. First, secular trends (i.e., trends over time) in fertility determine the sizes of future cohorts of youth and thus affect the ease with which recruiting targets can be met. The absolute sizes of cohorts of women of childbearing age and the rates at which those women bear children determine the numbers of children in each year. These numbers are also augmented by immigration of children and teenagers and depleted by mortality and emigration of these groups, but these effects on the youth population are small relative to fertility. Second, trends and levels of differential fertility affect each youth cohorts’ average propensity to enlist in the armed forces. The family environments in which young persons are raised affect their propensities to enlist or to engage in other activities that may complement or substitute for military service. These environments are affected by the socioeconomic characteristics of families, their size and structure, and other aspects of parents’ social backgrounds. Adults from different kinds of families bear children at different rates, with these differentials often varying over time. Other things being equal, therefore, fluctuations in these patterns of differential fertility will affect the average enlistment propensities of later cohorts of offspring when they reach the appropriate age for military service.

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment Third, demography is concerned with the activities of young persons themselves, without regard to the characteristics of the families in which they were raised. The propensity to enlist in the military is connected in a complex way to the other activities and opportunities faced by youths. These include schooling, work, marriage, childbearing, living arrangements, leisure, and possibly crime and incarceration. As these activities and opportunities have changed over time, so has the attractiveness of military service. As we consider the impact of demographic trends on recruitment into the armed forces, we take two perspectives on the youth population. One perspective, which we term “young adult demography,” focuses on recent trends in the activities and statuses of the youth population. This provides background for understanding recent trends in enlistment behavior. The second perspective, which we term “child demography,” looks at recent trends in fertility, including overall levels as well as differentials across social groups. These trends, which correspond to the first two ways in which demographic trends may affect military recruitment, provide a window on the future youth population over the next 15 to 20 years and thus a way of forecasting the size and makeup of the target population for recruitment. Because mortality and emigration rates are very low during the first 20 years of life, we can use recent trends in numbers of births to forecast the size and makeup of the youth population when recent birth cohorts will reach an appropriate age for service in the armed forces. In this chapter, we first describe key recent trends in the activities of young persons, focusing particularly on the school enrollment, employment, and enlistment patterns of youth and rates of college attendance of civilian youth. Then we describe the numbers and demographic composition of cohorts of children who will be reaching the eligibility age for service in the Armed Forces over the next two decades. We focus on characteristics of children and their parents that may affect their likelihood of entry into the armed forces and develop a rudimentary statistical model for predicting the likelihood of enlisting among demographic groups. Using this model and known trends in demographic characteristics, we can assess the implications of demographic trends for future numbers and rates of enlistment. YOUNG ADULT DEMOGRAPHY Upon high school graduation, youth typically face a menu of options about the major activities in which they will engage. These activities include further schooling, participation in the civilian workforce, service in the military, marriage, childbearing, and possibly other activities as well.

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment At least some of these activities may be pursued simultaneously, and others may be pursued in sequence. However, although decisions about what to do after leaving high school are not irreversible and considerable diversity and flexibility of choices are available to youth, the pursuit of nonmilitary options necessarily diminishes their availability for military service. The principal activities that “compete” with military service for recent high school graduates are further schooling and civilian employment. The trade-offs among these alternatives shift substantially over time because of both fluctuations in the civilian economy and secular trends in the aspirations of youth. In this section, we describe recent trends in schooling, work, and enlistment in the armed forces for young persons, focusing primarily on recent high school graduates, typically the target population for armed forces recruitment. Trends in Educational Attainment Perhaps the most dramatic secular trend in the youth population during the 20th century has been the growth in school enrollment and educational attainment, a trend that has continued unabated during the past several decades. Figures 3-1 and 3-2 show the trends in proportions of young men and women (ages 25–29) who have completed selected levels of schooling from 1970 to 1999.1 These trends show substantial increases in educational attainment for cohorts reaching adulthood during this period. For example, in 1970 only about 40 percent of men ages 25–29 had completed at least some college, whereas by 1999, more than 55 percent had done so. In the 1990s, the fraction of new cohorts of adults who completed four years of college began to accelerate, a reflection of increasing rates of college attendance throughout the decade (discussed below). The upward trend in educational attainment is even sharper for women than for men, showing a steady secular increase to a point such that now the average attainment level for women exceeds that of men. The difference in the trends for men and women is largely a result of unusually high rates of college attendance for men during the late 1960s and early 1970s, in all likelihood a response to the Vietnam-era draft and the availability of draft deferments for college students. Following the Vietnam era, the trend in men’s educational attainment reverted to what would have been expected on the basis of pre-Vietnam-era education trends. 1   This age group is young enough to provide some indication of the education levels of recent labor force entrants but old enough that most members of the birth cohort have completed their education. These data include both the civilian noninstitutional and armed forces populations in this age group.

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment FIGURE 3-1 Trends in educational attainment for men ages 25–29. SOURCES: Adapted from October Current Population Surveys (U.S. Bureau of the Census, 2002b) and unpublished U.S. Department of Defense data. As we discuss throughout this report, the expectations and aspirations of youth about their educational attainment have an important impact on their propensity to enlist in the armed forces as well as their actual enlistment behavior. Trends in educational attainment also, to some degree, affect the makeup of armed forces population itself, although trends in educational attainment of the youth population as a whole are not closely mirrored in the enlisted population. Figures 3-3a and 3-3b show trends in the educational makeup of male enlisted members of the armed forces for two age groups, ages 18–24 and 25–29. Figures 3-4a and 3-4b show the same trends for women. These figures show that persons with a high school degree and no higher educational credential have been a large plurality of the enlisted population throughout the past 30 years, although persons in other education groups

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment FIGURE 3-2 Trends in educational attainment for women ages 25–29. SOURCES: Adapted from October Current Population Surveys (U.S. Bureau of the Census, 2002b) and unpublished U.S. Department of Defense data. have increased in representation in recent years. Most importantly, a substantially increasing proportion of enlisted men and women have some postsecondary education. This results from trends in the educational makeup of persons who enlist in the armed forces, as well as increases in the numbers of enlistees who earn college credit while serving in the military. Activities of Recent High School Graduates The principal activities of youth are school enrollment and market work. In this section we briefly review trends in enrollment and employment of persons who have recently left high school. The discussion is

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment FIGURE 3-3 Trends in educational attainment for male members of the armed forces: a, ages 18–24; b, ages 25–29. SOURCE: Adapted from unpublished U.S. Department of Defense data.

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment FIGURE 3-4 Trends in educational attainment for female members of the armed forces: a, ages 18–24; b, ages 25–29. SOURCE: Adapted from unpublished U.S. Department of Defense data.

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment based on data from the October Current Population Survey, an annual survey of the civilian noninstitutional population of the U.S. Bureau of the Census that focuses on school enrollment and employment, as well as unpublished Department of Defense data. Trends in College Enrollment Corresponding to the large increases in educational attainment shown in Figures 3-1 and 3-2 are corresponding increases in rates of college enrollment by recent high school graduates. Figure 3-5 shows college enrollment rates of new high school graduates over the past three decades. These rates, based on the civilian noninstitutional population, apply to persons who graduated from high school during the previous 12 FIGURE 3-5 Trends in college enrollment of recent high school graduates. SOURCE: Adapted from October Current Population Surveys (U.S. Bureau of the Census, 2002b).

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment months. Overall fractions of recent high school graduates who attend college have grown dramatically during this period, ranging from less than half in the early 1970s to approximately two-thirds in the late 1990s.2 Although increases in attendance rates have occurred for both two- and four-year institutions, the bulk of the increase has been for four-year enrollments. In 1970, approximately half of college entrants entered two-year colleges. By 2000, only about one-third of new entrants went to two-year colleges. Although college enrollment rates have risen for the youth population as a whole, the increases in enrollment have varied among demographic groups. As shown in Table 3-1, enrollment rates for women have been more substantial than for men. Whereas men’s enrollments have increased by about 7 percentage points over the past 30 years, women’s rates have increased from less than 40 to almost 70 percent, reversing a traditional pattern of higher enrollment levels for men. Enrollment trends have also varied across major race-ethnic groups. Black enrollment rates did not keep up with the growth in white rates during the 1980s and indeed declined for several years (Figure 3-6). During the 1990s, however, the gap between black and white enrollment rates has closed considerably. The trend for Hispanic youth is unclear because of considerable sampling variability in the Current Population Survey data for this group. So far as it is possible to tell, Hispanic youth have not experienced the same increases in college enrollment rates that are seen for non-Hispanic whites and blacks. Trends in Employment and Enrollment Figures 3-7 and 3-8 show trends in school enrollment, civilian employment, and participation in the armed forces for persons ages 18 and 19 over the past three decades for men and women, respectively. The fraction of 18- and 19-year-old men who participate in the armed forces has declined steadily over much of the past 30 years, although this fraction was stable in the late 1990s. Participation in the armed forces is extremely low for women throughout this period when considered in the context of the entire 18- and 19-year-old female population. The long-term decline in armed forces participation for men implies that they have increasingly pursued civilian activities. We have already noted the substantial increase in proportions of recent high school graduates who attend college. In addition to the growth in school enrollment, there have been significant changes in rates of employment for youth. The 2   Attendance rates were unusually high prior to 1973 because of the draft exemption of college students during that period.

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment TABLE 3-1 College Enrollment of Recent High School Graduates: 1970– 1999   Number of High School Graduates Percentage Enrolled in Collegea Year Totalb Male Female White Black Totalb Male Female White Black 1970 2,757 1,343 1,414 2,461 (NA) 51.8 55.2 48.5 52.0 (NA) 1975 3,186 1,513 1,673 2,825 (NA) 50.7 52.6 49.0 51.2 (NA) 1980 3,089 1,500 1,589 2,682 361 49.3 46.7 51.8 49.9 41.8 1982 3,100 1,508 1,592 2,644 384 50.6 49.0 52.1 52.0 36.5 1983 2,964 1,390 1,574 2,496 392 52.7 51.9 53.4 55.0 38.5 1984 3,012 1,429 1,583 2,514 438 55.2 56.0 54.5 57.9 40.2 1985 2,666 1,286 1,380 2,241 333 57.7 58.6 56.9 59.4 42.3 1986 2,786 1,331 1,455 2,307 386 53.8 55.9 51.9 56.0 36.5 1987 2,647 1,278 1,369 2,207 337 56.8 58.4 55.3 56.6 51.9 1988 2,673 1,334 1,339 2,187 382 58.9 57.0 60.8 60.7 45.0 1989 2,454 1,208 1,245 2,051 337 59.6 57.6 61.6 60.4 52.8 1990 2,355 1,169 1,185 1,921 341 59.9 57.8 62.0 61.5 46.3 1991 2,276 1,139 1,137 1,867 320 62.4 57.6 67.1 64.6 45.6 1992 2,398 1,216 1,182 1,900 353 61.7 59.6 63.8 63.4 47.9 1993 2,338 1,118 1,219 1,910 302 62.6 59.7 65.4 62.8 55.6 1994 2,517 1,244 1,273 2,065 318 61.9 60.6 63.2 63.6 50.9 1995 2,599 1,238 1,361 2,088 356 61.9 62.6 61.4 62.6 51.4 1996 2,660 1,297 1,363 2,092 416 65.0 60.1 69.7 65.8 55.3 1997 2,769 1,354 1,415 2,228 394 67.0 63.5 70.3 67.5 59.6 1998 2,810 1,452 1,358 2,227 393 65.6 62.4 69.1 65.8 62.1 1999 2,897 1,474 1,423 2,287 453 62.9 61.4 64.4 62.8 59.2 SOURCE: U.S. Bureau of the Census (2001). NOTE: High school graduates in thousands. For persons 16 to 24 who graduated from high school in the proceeding 12 months. Includes persons receiving GEDs. NA=not available. aAs of October. bIncludes other races, not shown separately. proportion of young men and women who adopt a “work-only” pattern shortly after leaving high school has dropped substantially over this period, a trend that is offset by both an increase in the proportions who adopt a “school-only” pattern and who combine school enrollment with employment. Young persons are increasingly using work as a means of financing further education, as well as pursuing additional schooling while earning a living. A key feature of these trends is that these developments have occurred in tandem for men and women and, in general, women’s activity patterns have come increasingly to resemble those of men.3 3   In Figures 3-7 and 3-8 individuals must work 20 or more hours a week to be considered “employed.” Using a less stringent definition of employment would result in higher estimated proportions of persons who are employed or both employed and enrolled. The trends in these proportions, however, are similar to those reported in Figures 3-7 and 3-8.

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment FIGURE 3-6 College enrollment rates of high school graduates, by race-ethnicity. SOURCE: Adapted from October Current Population Surveys (U.S. Bureau of the Census, 2002b). FUTURE SIZE AND COMPOSITION OF THE YOUTH POPULATION Trends in the Size of the Youth Population We can estimate the size of the youth population with reasonable reliability for the next two decades. Because all persons who will reach age 18 over the next 18 years have already been born, recent fertility trends provide the core data for future estimates of the size of this population. The Census Bureau routinely calculates projections of the size of the population specific to age, sex, race-ethnicity, and nativity (native-born versus foreign-born). Although the Census Bureau makes projections as far as 100 years in the future, from the standpoint of estimating the number of persons of a suitable age to enter the armed forces, we can be most confident of the estimates for cohorts that are already born. For example, because the cohort that will be age 18 in 2015 was born in 1997, its initial size is already known from 1997 birth records, and it is thus necessary to forecast only future mortality, immigration, and emigration. In contrast, the cohort that will reach age 18 in 2025 is not yet born and

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment FIGURE 3-13 Proportion of births by education of mother and year reaching age 18. SOURCE: Adapted from June Current Population Surveys (U.S. Bureau of the Census, 2002a). NOTE: These estimates are based on birth history data from microdata from the June Current Population Surveys of 1975, 1980, 1985, 1990, 1995, and 2000. Estimates are based on births occurring up to five years prior to the survey date. Similar trends would be observed for births classified by levels of father’s education (not shown here). milestones in the educational process (e.g., high school degree, some college, college degree). That is, parental educational attainments tend to set a “floor” beneath the educational attainments of their children. In particular, whether parents have completed at least some college has a particularly large impact on whether their offspring complete at least some college (Mare, 1995). As shown in Figure 3-13, the proportion of births to women with at least some college has jumped sharply in recent years and, despite considerable short-term fluctuations, shows no sign of declining. This suggests that even in the absence of changes in the economic incentives that affect the relative desirability of alternative levels of schooling, youth will increasingly seek higher education during the next two decades.

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment Parents’ Occupations Another aspect of the family environment that affects young persons’ aspirations and their propensities to engage in various activities after high school is the work roles of their parents. Youths’ occupational aspirations are, in part, a reflection of the occupations and socioeconomic levels of their parents. Although both upward and downward mobility are common in the United States, parents’ socioeconomic levels tend to set a floor on the aspirations of their offspring. Across cohorts, young persons’ family environments change because of secular transformations of the occupational structure and changing rates of adult labor force participation. Figures 3-14 and 3-15 present trends from 1970 to 2000 in the proportions of births to fathers and mothers in broad occupational groups. Over this period, an increasing proportion of births are to couples in which fathers and mothers have managerial, professional, or technical occupations. This reflects the general drift in the occupational structure toward a professional, nonmanual workforce and a relative decline in manual occupations. In addition, a shrinking proportion of births are to mothers who have never worked. These trends, which illustrate the family backgrounds of cohorts that will reach adulthood over the next two decades, show that young persons are increasingly raised in families in which at least one parent has a managerial or professional job. It suggests that future cohorts of potential enlistees may have higher occupational aspirations than their counterparts in the past. Parents’ Military Service A further element of the family environment that may affect propensity to serve in the armed forces is whether children are raised by parents who have had military experience. Insofar as parents are the primary influencers of their children, and nonfamily influences, such as schools and peer groups, provide no direct contact with the military, children whose parents served in the armed forces may receive unique information about the possibility of service. Over time, the proportion of children who are raised in families with experience in the armed forces varies considerably, because cohorts of adult Americans have varied in whether they entered adulthood during times of peace or war and during times in which policies of conscription or volunteer forces were in effect. The proportion of a cohort of children who had one or more parents who served in the armed forces is affected primarily by how common military service was when the parents’ generation was in its late teens and early twenties, and secondarily by the differential fertility of men and women who served in the military at some point in their lives compared

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment FIGURE 3-14 Proportion of births to families by occupation of father and year. SOURCE: Adapted from June Current Population Surveys (U.S. Bureau of the Census, 2002a). NOTE: These estimates are based on birth history data from microdata from the June Current Population Surveys of 1975, 1980, 1985, 1990, 1995, and 2000. Estimates are based on births occurring up to five years prior to the survey date. Estimates for fathers are based on couples in which the father is present in the household. with those who never served. If we consider cohorts born since 1970, we see a dramatic decline in the proportion of persons in each birth cohort whose fathers or mothers were veterans of the armed forces. Figure 3-16 reports estimates of the proportion of each birth cohort who had at least one parent who was a veteran at the time of the cohort member’s birth. These estimates show a dramatic decline, from approximately 40 percent of births occurring in 1970 to couples in which at least one parent was a veteran to approximately 8 percent of births in 2000. Of the cohort of youths reaching age 18 in 2000, approximately 18 percent had a father or a mother who was a veteran of the armed forces. Between 1982 and 2000, therefore, the fraction of cohorts of 18-year-olds with veteran parents

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment FIGURE 3-15 Proportion of births to families by occupation of mother and year. SOURCE: Adapted from June Current Population Surveys (U.S. Bureau of the Census, 2002a). NOTE: These estimates are based on birth history data from microdata from the June Current Population Surveys of 1975, 1980, 1985, 1990, 1995, and 2000. Estimates are based on births occurring up to five years prior to the survey date. Estimates for fathers are based on couples in which the father is present in the household. declined by more than 50 percent. Between 2000 and 2018, this fraction will decline again by more than 50 percent. This constitutes a dramatic reduction in the proportion of young persons who are raised by parents with military experience. A SIMPLE FORECASTING MODEL FOR MILITARY ENLISTMENT The trends in child demography shown in the previous section suggest that demographic influences may have offsetting effects on the propensity of future cohorts of youths to enlist in the armed forces. On one

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment FIGURE 3-16 Proportion of 18-year-olds born to one or more veteran parents. SOURCE: Adapted from June Current Population Surveys (U.S. Bureau of the Census, 2002a). NOTE: These estimates are based on birth history data from microdata from the June Current Population Surveys of 1975, 1980, 1985, 1990, 1995, and 2000. Estimates are based on births occurring up to five years prior to the survey date and use information on whether the mother or the resident father had served in the armed forces prior to the survey date. hand, successive cohorts of youths will increase during the next decade, thereby enlarging the pool of potential enlistees. On the other hand, future cohorts of youths may increasingly opt for higher education at the expense of other postsecondary options, including direct entry into the civilian workforce or service in the armed forces. To appraise the net effect of these potentially offsetting forces requires a model of how they work together. Our approach to this is (1) to estimate a simple logistic regression of the effects of a small number of family background factors on the probability of enlistment in the armed forces, using panel data for a single cohort of youths and (2) to use the estimated coefficients, in combination with the annual series of birth statistics based on the June Current Population Surveys from 1970 to 2000, to compute the predicted probability of enlistment and total number of enlistees in the armed forces for each birth cohort represented in the June Current Population Survey. The strength of this procedure is that is it a useful way to combine disparate influences and see their net effects. Moreover, it makes clear the logical steps needed to extrapolate from recent trends. Of course, the drawback to this procedure is that it makes several strong assumptions

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment that may not be accurate. In particular, it assumes that the relationships between the demographic factors and the probability of enlistment that are estimated for a single birth cohort will hold over the entire forecasting period. It also ignores economic, political, and cultural factors that may deflect enlistment rates from the long-term trajectory implied by recent fertility patterns. On balance, this method should be viewed as a way of seeing the effects of known demographic trends, rather than an accurate forecast of enlistment rates and numbers. We estimate the model for the effects of demographic factors on enlistment using the National Longitudinal Survey of Youth (NLSY79), a panel of youths ages 14–22 in 1979 who were followed annually until 1994 and biennially thereafter (U.S. Bureau of Labor Statistics, 2002c). Although these data provide a rich array of potential proximate determinants of military enlistment, including civilian work experience, aptitude test scores, living arrangements, etc., we focus only on demographic characteristics that are known at birth. Only the latter, of course, are known for cohorts that are still too young to serve in the armed forces. These demographic characteristics include mother’s educational attainment, race-ethnicity, whether one or more parents served in the armed forces, and region of birth.4 Separate models are estimated for men and women. Table 3-3 presents the estimated logit coefficients from these models. Figure 3-17 shows the implied trend in the probability of enlistment for cohorts reaching age 18 between 1989 and 2017. The implied cohort enlistment rates decline by approximately 10 percent over this period, with a roughly constant decline per year. It is important to recognize that these overall enlistment rates are considerably higher than the actual rates during the 1990s, a result of relying on the NLSY79 cohort for the underlying prediction model. Provided that the effects of the demographic characteristics have not changed much over time, however, the secular trend in predicted cohort enlistment rates would not change even were we to 4   Father’s educational attainment is not included in the model because it is highly correlated with mother’s educational attainment and thus adds little to the predictive power of the model. Region of birth is a dichotomous variable denoting whether or not an individual was born in the South. Persons of Southern origin are somewhat more likely to enlist in the armed forces than persons born elsewhere. Over cohorts, the proportion of persons born in the South increased slightly between 1970 and 2000. Parents’ occupations are not included in the model because the NLSY79 does not include measures of parents’ occupation at the time of birth of respondents, which are the measures available in the birth data. Although persons whose parents have professional and managerial occupations are somewhat less likely to enlist than persons whose parents have other occupations, their estimated net effects are small once parental education is taken into account.

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment TABLE 3-3 Logit Coefficient Estimates for Model Predicting Probability of Enlistment in the Armed Forces Independent Variables Logit B Robust S.E.(B) z P>z Men Parent in armed forces .185 .087 2.1 .03 South .229 .092 2.5 .01 Mother high school diploma (vs. HS dropout) –.098 .098 –1.0 .31 Mother some college (vs. HS dropout) –.230 .154 –1.5 .14 Mother college degree or more (vs. HS dropout) –.533 .170 –3.1 .00 Black (vs. non-Hispanic white) .400 .098 4.1 .00 Hispanic (vs. non-Hispanic white) –.136 .138 –1.0 .33 Other (vs. non-Hispanic white) .117 .143 .8 .41 Intercept –1.577 .104 –15.2 .00 Log likelihood = –2666.1; N = 5663 Women Parent in armed forces .444 .192 2.3 .02 South –.177 .195 –.9 .36 Mother high school diploma (vs. HS dropout) .246 .202 1.2 .23 Mother some college (vs. HS dropout) .281 .309 .9 .36 Mother college degree or more (vs. HS dropout) .091 .389 .2 .82 Black (vs. non-Hispanic white) .919 .197 4.7 .00 Hispanic (vs. non-Hispanic white) .298 .358 .8 .41 Other (vs. non-Hispanic white) –.203 .380 –.5 .59 Intercept –3.938 .211 –18.7 .00 Log likelihood = –774.1; N = 5623   SOURCE: Center for Human Resource Research (2000). adjust the levels of the rates downward to agree with those observed in the 1990s. To see the impact of these effects on overall expected numbers of enlistees, we multiply each predicted probability of enlistment by the size of the 18-year-old population as projected by the Census Bureau.5 These estimates, however, drastically overstate recent and probably future enlistment levels because they are based on a model estimated in an earlier period when enlistment levels were much higher. To obtain a somewhat more realistic view of enlistment levels, we calibrate the estimates to agree 5   Male and female enlistment trends are combined to yield the total numbers of enlistees presented in Figure 3-17.

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment FIGURE 3-17 Trend in proportions ever enlisting implied by trends in mother’s education, race-ethnicity, parents’ veteran status, and region of birth. SOURCES Authors’ calculations from National Longitudinal Survey of Youth (Center for Human Resource Research, 2000); June Current Population Surveys (U.S. Bureau of the Census, 2002a); birth records from National Center for Health Statistics natality statistics microdata files (National Center for Health Statistics, 2002). with the number of first-time enlistments in 1997 but otherwise preserve the trend implied by the model (U.S. Bureau of the Census, 2002a, 2002b).6 Figure 3-18 shows these estimates for the period from 1989 to 2017. Our 6   This calibration procedure consists of multiplying the predicted number of enlistees in each year by the ratio of the actual number of first-time enlistees in 1997 by the number of enlistees predicted by the model for 1997. This ratio is approximately 0.46. This procedure is likely to yield an overestimate of the number of 18-year-old enlistees in each year because the published number of first-time enlistees is not confined to 18-year-olds. Under the assumption that the age distribution of new enlistees does not change appreciably over time, however, this method does yield a plausible estimate of the number of new enlistees of any age, rather than just at age 18.

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment FIGURE 3-18 Expected number of potential enlistees at age 18 based on trends in births and child demographic characteristics. SOURCES Authors’ calculations from National Longitudinal Survey of Youth (Center for Human Resource Research, 2000); June Current Population Surveys (U.S. Bureau of the Census, 2002a); birth records from National Center for Health Statistics natality statistics microdata files (National Center for Health Statistics, 2002). estimates, however, nonetheless illustrate the trend in enlistments implied by recent demographic trends. These estimates strongly suggest that, despite the downward drift in enlistment rates that is implied by the changing family backgrounds of future youth cohorts, there will be somewhat of an increase in expected numbers of enlistees. Secular growth in the size of youth cohorts almost completely offsets the downward trend in enlistment rates implied by trends in parental education and parents’ experience with the armed forces. SUMMARY Demographic trends in the youth population place fundamental constraints on armed forces recruitment. The size and composition of the youth population will affect future recruitment efforts. We can forecast the size and some aspects of the composition of the youth population for the next 15 to 20 years with some accuracy because these persons are

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment already born. Cohorts of persons reaching 18 years of age are expected to grow significantly over the next 10 years and then remain approximately at a plateau during the following decade. Approximately 4 million youth reached age 18 in 2000, a number that will increase to approximately 4.4 million by 2008 and trail off to between 4.1 and 4.2 million during the subsequent decade. The ethnic composition of the youth population will change significantly over the next 15 to 20 years (even in the absence of changes in immigration patterns) because of recent changes in the ethnic makeup of women of childbearing age and ethnic differences in fertility rates. In particular, based on recent fertility and immigration patterns, the percentage of young adults who are Hispanic will increase substantially. A growing percentage of youth will be raised by parents who are immigrants to the United States, a result of high rates of recent immigration and relatively high fertility levels of foreign-born women. In addition to the size and composition of the youth population, trends in parental characteristics and in the activities of youth affect armed forces recruitment. During the 1990s, rates of college enrollment and levels of education completed increased dramatically as a result of three broad trends: (1) secular changes in parental characteristics, especially parents’ educational attainment, which increased youths’ resources and aspirations for education; (2) the greater inclusion in higher education of women and some ethnic minorities; and (3) increased economic incentives to attend and complete college, a result of changes in the labor market for college- and non-college-educated workers (as discussed in Chapter 5, this volume). Recent trends also show that youth are increasingly using work as a means to finance additional schooling and that they do so by pursuing an education while earning a living. Increases in educational attainment in the population will continue over the next two decades. Average levels of maternal education have increased markedly and, in the future, the majority of youths will be raised by mothers who have completed at least some college. Parents’ educational attainment has a large effect on the aspirations and decisions of youths, especially concerning higher education. While youth are expected to have at least one parent with at least some college in the coming years, the proportion of young adults who have had at least one parent with military experience has fallen dramatically and will continue to fall in the coming years. This represents a large decline in exposure to military experience within the nuclear family. In sum, trends in the numbers of births and in the composition of the child population have offsetting effects on potential enlistment trends. Although the annual number of births has increased in recent years, children are increasingly raised by highly educated parents and by parents

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Attitudes, Aptitudes, and Aspirations of American Youth: Implications for Military Recruitment who have no direct experience with the armed forces. The net impact of these offsetting trends is a small increase in expected numbers of enlistees in the next decade, implying that the supply of young persons will be large enough to meet recruitment goals. This conclusion refers to the expected impact of demographic trends alone. Thus, demographic trends do not emerge as factors that will contribute to increasing difficulty in meeting enlistment goals. Other factors discussed in this report, including advertising and recruitment practices, will determine whether potential enlistees actually enlist at a rate necessary to meet goals.