The IPUMS Multigenerational Longitudinal Panel (MLP) is a longitudinal population panel that links American censuses, surveys, administrative sources, and vital records spanning the period from 1850 to the present. This article explains the rationale for IPUMS MLP, outlines the design of the infrastructure, and describes the linking methods used to construct the panel. We then detail our plans for expansion and improvement of MLP over the next five years, including the incorporation of additional data sources, the development of a "linkage hub" to connect MLP with other major record linkage efforts, and the refinement of our technology and dissemination efforts. We conclude by describing a few early examples of MLP-based research.

<p>We estimate the extent to which the methodological problem called panel conditioning biases the federal government’s estimates of the prevalence of food insecurity in the United States. To do so, we use 2002 through 2020 data from the Current Population Survey’s Food Security Supplement—the same data used to produce the federal government’s annual statistics about food insecurity. We take advantage of the CPS’s rotating panel design feature to estimate the effects of panel conditioning. By comparing CPS respondents who participated in the Food Security Supplement in each of two consecutive years but who—strictly by chance—were selected to begin the CPS one year apart, we both approximate an experimental design and derive estimates of panel conditioning that are purged of biases from panel attrition. For the 200,000+ unique households in our sample, the treatment is having previously participated in the Food Security Supplement; the outcome is participants’ subsequent responses to survey questions about food security. We find that in nearly every year people in the treatment group—that is, the group of people who have previously responded to the Food Security Supplement—are less likely to be food insecure than people responding for the first time. These differences are statistically significant and large in magnitude. We conclude that the federal government’s estimates of the prevalence of food insecurity in America are substantially biased; depending on the mechanism underlying panel conditioning, the true prevalence of food insecurity may be substantially higher or lower than officially reported.</p>

<p>Recent research concludes that professional American football players (hereafter, “football players”) live longer than American men in general, despite experiencing higher rates of chronic traumatic encephalopathy (CTE) and cardiovascular disease (CVD). This suggests that the longevity-enhancing benefits of playing football (e.g., physical fitness, money) outweigh the costs associated with CTE, CVD, and other longevity detriments of playing football. However, these surprising results may be the consequence of flawed research design. To investigate, we conducted two analyses. In analysis 1, we compared a) all professional American football players whose first season was 1986 or between 1988 and 1995 to b) a random sample of same-age American men observed as part of the National Health Interview Surveys in those same years selected on good health, at least 3 y of college, and not being poor. The exposure consists of playing one or more games of professional football; the outcome is risk of death within 25 y. In analysis 2, we use data on 1,365 men drafted to play in the (American) National Football League in the 1950s—906 of whom ultimately played professional football, and 459 of whom never played a game in any professional league. We estimate the association between playing football and survival through early 2023. In both analyses, we investigate differences between linemen and other position players. In contrast to most prior research, in both analyses, we find that linemen died earlier than otherwise similar men; men who played other positions died no earlier (or later).</p>

For a quarter of a century researchers have been documenting and trying to explain trends in Americans’ vocabulary knowledge using data from the General Social Survey (GSS) and its WORDSUM test. Trends in Americans’ vocabulary knowledge have important practical implications—for example, for educational policy and practice—and speak to the American workforce’s competitiveness in the global knowledge economy. We contribute to this debate by analyzing 1978–2018 GSS data using an improved analytical approach that is consistent with theoretical notions of cohort effects and that permits simultaneously estimating inter-cohort average differences and intra-cohort life-course changes. We find that WORDSUM scores peak around age 35 and gradually decline in older ages; the scores were significantly lower in the 1980s and higher in the late 2000s and 2010s; and the 1940–1954 birth cohorts and the 1965 and later birth cohorts had notably higher and lower scores, respectively, than the expectation based on age and period main effects. We provide new evidence that such cohort differences tend to persist over the life course. Interestingly, the effects of increasing educational attainment and decreasing reading behaviors seemed to cancel out, leading to a relatively flat overall period trend. Trends in television viewing and word obsolescence did not appear to affect age, period, or cohort trends in WORDSUM scores.

<p>Racism is embedded in society, and higher education is an important structure for patterning economic and health outcomes. Historically Black Colleges and Universities (HBCUs) were founded on anti-racism while predominantly white institutions (PWIs) were often founded on white supremacy. This contrast provides an opportunity to study the association between structural racism and health among Black Americans. We used the National Longitudinal Study of Adolescent to Adult Health (Add Health) to estimate the long-term causal effect of attending an HBCU (vs. PWI) on depressive symptoms among Black students in the United States from 1994-2018. While we found no overall association with attending an HBCU (vs. PWI) on depressive symptoms, we found that this association varied by baseline mental health and region, and across time. For example, among those who attended high school outside of the South, HBCU attendance was protective against depressive symptoms 7 years later, and the association was strongest for those with higher baseline depressive symptoms. We recommend equitable state and federal funding for HBCUs, and that PWIs implement and evaluate antiracist policies to improve mental health of Black students.</p>

The Flint, Michigan water crisis renewed concern about lead toxicity in drinking water. While lead in drinking water has been shown to negatively affect cognition among children, much less is known about its long-term consequences for late-life cognition. Using a nationally representative sample of U.S. older adults linked to historical administrative data from 1940, we find that older adults who lived as children in cities with lead pipes and acidic or alkaline water—the conditions required for lead to leach into drinking water—had worse cognitive functioning but not steeper cognitive decline. About a quarter of the association between lead and late-life cognition was accounted for by educational attainment. Within the next 10 years, American children exposed to high levels of lead during the 1970s will enter older ages. Our evidence highlights the need for stronger actions to identify interventions to mitigate long-term damage among people at high risk.

We examine the socioeconomic consequences of discrimination against people of Southern origins during the US Great Migration of the first half of the twentieth century. We ask whether people living in the American North and Midwest in 1940 fared worse with respect to education, occupation, and income if they were perceived to be of Southern origins. We also assess variation in these effects across racial groups and across actual region of origin groups. Using linked data from the 1920 and 1940 US censuses, we compare the life outcomes of about half a million pairs of brothers who differed with respect to the regional origin implied by their first names. For both Whites and Blacks, we find statistically significant associations between outcomes and the regional origin implied by names; regardless of where they were born, men living in the North or Midwest in 1940 did worse if their names implied Southern origins. However, these associations are entirely confounded by family-specific cultural, socioeconomic, and other factors that shaped both family naming practices and life outcomes. This finding - that regional discrimination in the early-twentieth-century United States did not happen based on names - contrasts sharply with findings from research in more recent years that uses names as proxies for people's risk of exposure to various forms of discrimination. Whereas names are a basis for discrimination in modern times, they were not a basis for regional discrimination in an era in which people had more immediate and direct evidence about regional origins.

Childhood malnutrition and its later life effects were important concerns in European and North American social policy in the early twentieth century. However, there have been few studies of the lo...

Introduction: Lead exposure negatively affects cognitive functioning among children. However, there is limited evidence about whether exposure to lead in early life impairs later life cognitive functioning. Methods: Participants in the prospective Wisconsin Longitudinal Study cohort (N = 8583) were linked to the 1940 Census, which was taken when they were young children. We estimated the effect of living near a lead mine in childhood on late life memory/attention and language/executive function in 2004 (mean age 64) and 2011 (mean age 71). Results: Lead-exposed children had significantly steeper memory/attention decline between 2004 and 2011 and worse language/executive function at baseline in late life. These long-term effects of lead were not mediated through adolescent IQ or late life SES and health factors. Discussion: Proximity to lead mining in childhood had long-term effects on late life memory/attention decline and language/executive function, reflecting a possible latent influence of lead exposure. More research is needed to understand behavioral and biological pathways underlying this relationship.

There is considerable evidence that the act of participating in a survey can alter participants' attitudes, behaviors, and other outcomes in meaningful ways. Considering findings that this form of panel conditioning also impacts health behaviors and outcomes, we investigated the effect of participating in an intensive half-century-long cohort study on participants’ longevity. To do so, we used data from a 1957 survey of more than 33,000 Wisconsin high school seniors linked to mortality records. One third of those people were selected at random to participate in the Wisconsin Longitudinal Study (WLS); the other two thirds were never again contacted. Our survival models show no evidence of panel conditioning effects on longevity: People selected at random to participate in the WLS had the same mortality outcomes as their peers who were not selected. This finding holds for the full sample, for women, for men, for population subgroups defined by family socioeconomic origins and educational experiences, and for treatment compliers.

Objective: Assess the association of BMI and BMI change with mortality. Methods: Using data from the Wisconsin Longitudinal Study (WLS) on participants born mainly in 1939 (n=4922), we investigated the associations between various measures of BMI across the life course (age 54 BMI; age 65 BMI; age 72 BMI; lifetime maximum BMI; BMI change between ages 54 and 65; BMI change between ages 65 and 72) and mortality. We also assessed whether these associations are mediated by late life health. Results: BMI at age 54 was more strongly associated with late life mortality than BMI at older ages. The association between BMI change and mortality varied based on the timing of weight change. Health at age 72, particularly self-rated health, diabetes, and physical functioning, mediated the observed associations. Conclusion: Knowing older people’s weight at midlife and how their weight has changed may be more important in assessing late life mortality risk than their current weight.

The economic characteristics of one’s childhood neighborhood have been found to deter mine long-term well-being. Policies enacted dur ing child hood may change neighborhood trajectories and thus impact long-term outcomes for children. We use individual-level data from the Wisconsin Longitudinal Study to examine the enduring consequences of childhood exposure to local-area New Deal emergency employment work-relief activ ity. Our out comes include ado les cent cog ni tion, edu ca tional attain­ment, mid­life income, health behav­iors, late-life cog­ni­tion, and mor­tal­ity. We find that children (ages 0–3) living in neighborhoods with moderate work-relief activity in 1940 had higher adolescent IQ scores, had higher class rank, and were more likely to obtain at least a bach­e­lor’s degree. We find endur­ing ben­e­fits for mid­life income and late-life cognition for males who grew up in areas with a moderate amount of work relief. We find mixed results for males who grew up in the most dis­ad­van­taged areas with the highest levels of work-relief activity. These children had similar educational outcomes as those in the most advantaged districts with the lowest work-relief activity but had higher adult smok­ing rates. Our find­ings pro­vide some of the first evi­dence of the long-term consequences of New Deal policies on children’s long-term life course outcomes.