Severe prenatal shocks and adolescent health: Evidence from the Dutch Hunger Winter.

This paper investigates health impacts at the end of adolescence of prenatal exposure to multiple shocks, by exploiting the unique natural experiment of the Dutch Hunger Winter. At the end of World War II, a famine occurred abruptly in the Western Netherlands (November 1944-May 1945), pushing the previously and subsequently well-nourished Dutch population to the brink of starvation. We link high-quality military recruits data with objective health measurements for the cohorts born in the years surrounding WWII with newly digitised historical records on calories and nutrient composition of the war rations, daily temperature, and warfare deaths. Using difference-in-differences and triple differences research designs, we first show that the cohorts exposed to the Dutch Hunger Winter since early gestation have a higher Body Mass Index and an increased probability of being obese at age 18. We then find that this effect is partly moderated by warfare exposure and a reduction in energy-adjusted protein intake. Lastly, we account for selective mortality using a copula-based approach and newly-digitised data on survival rates, and find evidence of both selection and scarring effects. These results emphasise the complexity of the mechanisms at play in studying the consequences of early conditions.

Early Home Visits and Health Outcomes in Low-Income Mothers and Offspring: 18-Year Follow-Up of a Randomized Clinical Trial.

Importance: Individuals with low income may have heightened rates of obesity and hypertension. Objective: To determine whether prenatal and infancy home visitation by nurses reduces maternal and offspring obesity and hypertension. Design, Setting, and Participants: This randomized clinical trial of prenatal and infancy nurse home visitation in a public health care system in Memphis, Tennessee, enrolled 742 women with no previous live births and at least 2 sociodemographic risk factors (unmarried, <12 years of education, unemployed) from June 1, 1990, through August 31, 1991. At registration during pregnancy, 727 mothers (98%) were unmarried, and 631 (85%) lived below the federal poverty level. At offspring ages 12 and 18 years, maternal and offspring obesity and hypertension were assessed by staff masked to treatment. The data analysis was performed from July 1, 2021, to October 31, 2023. Interventions: Women assigned to the control group received free transportation for prenatal care and child developmental screening and referral at child ages 6, 12, and 24 months. Women assigned to nurse visitation received transportation and screening plus prenatal and infant and toddler nurse home visits. Main Outcomes and Measures: Obesity and hypertension among mothers and their offspring at child ages 12 and 18 years, although not hypothesized in the original trial design, were analyzed using post-double selection lasso method. Results: Of the 742 participants randomized (mean [SD] age, 18.1 [3.2] years), interviews were completed with 594 mothers and 578 offspring at child age 12 years and 618 mothers and 629 offspring at child age 18 years. Obesity was assessed for 576 offspring at age 12 years and 605 at age 18 years and for 563 and 598 mothers at child ages 12 and 18 years, respectively. Blood pressure was assessed for 568 offspring aged 12 years and 596 aged 18 years and 507 and 592 mothers at child ages 12 and 18 years, respectively. There were no overall treatment-control differences in offspring obesity or hypertension at ages 12 and 18 years combined, although nurse-visited female offspring, compared with controls, had a lower prevalence of obesity (adjusted relative risk [ARR], 0.449; 95% CI, 0.234-0.858; P = .003) and severe obesity (ARR, 0.185; 95% CI, 0.046-0.748; P < .001). There were reductions at ages 12 and 18 years combined for stage 1 and stage 2 hypertension for nurse-visited vs control group mothers, with differences limited to mothers of females (stage 1: ARR, 0.613 [95% CI, 0.440-0.855; P = .001]; stage 2: ARR, 0.217 [95% CI, 0.081-0.582; P < .001]). For both obesity and hypertension outcomes, there was no intervention effect among male offspring or the mothers of males. Self-reported maternal health aligned with program effects on hypertension. Conclusions and Relevance: In this clinical trial follow-up at offspring ages 12 and 18, nurse-visited female offspring had lower rates of obesity and mothers of females had lower rates of hypertension than control-group counterparts. These findings suggest that risks for chronic disease among mothers of females and their female offspring who live in extreme poverty may be prevented with prenatal and infant and toddler home visitations by nurses. Trial Registration: ClinicalTrials.gov Identifier: NCT00708695.

Risk factors for natural menopause before the age of 45: evidence from two British population-based birth cohort studies.

BACKGROUND: Menopause that occurs before the age of 45 and is not medically induced (referred to here as 'early natural menopause') affects around one in 10 women and has serious health consequences. These consequences include increased risk of all-cause mortality, cardiovascular disease, osteoporosis, and type 2 diabetes. METHODS: We investigate risk factors for the onset of natural menopause before the age of 45 in two population-based prospective cohort studies in Britain: the 1958 cohort following 8959 women and the 1970 cohort following 8655 women. These studies follow women from birth to adulthood, and we use harmonized data on birth and early life characteristics, reproductive health, health behaviour, and socioeconomic characteristics for 6805 women who were pre-menopausal, peri-menopausal or had undergone natural menopause. Of these 6805 women, 3614 participated in the 1958 cohort (of which 368 had early menopause) and 3191 participated in the 1970 cohort (of which 206 had early menopause). Taking a life course approach, we focus on three distinct life stages - birth/early life, childhood, and early adulthood - to understand when risk factors are most harmful. Respecting the temporal sequence of exposures, we use a series of multivariable logistic regression models to estimate associations between early menopause and each potential risk factor adjusted for confounders. RESULTS: We find that early menopause is influenced by circumstances at birth. Women born in lower social class families, whose mother smoked during the pregnancy or who were breastfed 1 month or less were more likely to undergo early menopause. Early menopause is also associated with poorer cognitive ability and smoking in childhood. Adult health behaviour also matters. Smoking is positively correlated with early menopause, while regular exercise and moderate frequency of alcohol drinking in women's early thirties are associated with reduced risk of early menopause. The occurrence of gynaecological problems by women's early thirties is also linked to early menopause. CONCLUSIONS: We demonstrate that characteristics at different periods of life are associated with early menopause. Some of these associations relate to modifiable behaviours and thus the risks of early menopause and the adverse health outcomes associated with it may be preventable.

The consequences of early menopause and menopause symptoms for labour market participation.

Using a difference-in-difference estimator we identify the causal impact of early menopause and menopause symptoms on the time women spend in employment through to their mid-50s. We find the onset of early natural menopause (before age 45) reduces months spent in employment by 9 percentage points once women enter their 50s compared with women who do not experience early menopause. Early menopause is not associated with a difference in full-time employment rates. The number of menopause symptoms women face at age 50 is associated with lower employment rates: each additional symptom lowers employment rates and full-time employment rates by around half a percentage point. But not all symptoms have the same effects. Vasomotor symptoms tend not to be associated with lower employment rates, whereas the employment of women who suffer psychological problems due to menopause is adversely affected. Every additional psychological problem associated with menopause reduces employment and full-time employment rates by 1-2 percentage points, rising to 2-4 percentage points when those symptoms are reported as particularly bothersome.

The economic costs of child maltreatment in UK.

Child maltreatment is a major public health problem with significant consequences for individual victims and for society. In this paper, we quantify for the first time the economic costs of fatal and nonfatal child maltreatment in the UK in relation to several short-, medium-, and long-term outcomes ranging from physical and mental health problems to labor market outcomes and welfare use. We combine novel regression analysis of rich data from the National Child Development Study and the English Longitudinal Study of Aging with secondary evidence to produce an incidence-based estimate of the lifetime costs of child maltreatment from a societal perspective. The discounted average lifetime incidence cost of nonfatal child maltreatment by a primary caregiver is estimated at £89,390 (95% uncertainty interval £44,896 to £145,508); the largest contributors to this are costs from social care, short-term health, and long-term labor market outcomes. The discounted lifetime cost per death from child maltreatment is estimated at £940,758, comprising health care and lost productivity costs. Our estimates provide the first comprehensive benchmark to quantify the costs of child maltreatment in the UK and the benefits of interventions aimed at reducing or preventing it.

Overweight and obesity at age 19 after pre-natal famine exposure.

BACKGROUND: Weight for height has been used in the past as an indicator of obesity to report that prenatal exposure to the Dutch famine of 1944-1945 determined subsequent obesity. Further evaluation is needed as unresolved questions remain about the possible impact of social class differences in fertility decline during the famine and because being overweight is now defined by a Body Mass Index (BMI: kg/m2) from 25 to <30 and obesity by a BMI of 30 or more. METHODS: We studied heights and weights of 371,100 men in the Netherlands born between 1943 and 1947 and examined for military service at age 19. This group includes men with and without prenatal exposure to the Dutch famine. RESULTS: There was a 1.3-fold increase in the risk of being overweight or obese in young adults at age 19 after prenatal famine exposure in early gestation. The increase was only seen in sons of manual workers born in the large cities of Western Netherlands and not among those born in smaller cities or rural areas in the West. Social class differentials in fertility decline during the famine did not bias study results. CONCLUSIONS: The long-term adverse impact of prenatal famine on later life type 2 diabetes and mortality through age 63 is already showing at age 19 in this population as a significant increase in overweight risk.

Impact of lockdown on key workers: findings from the COVID-19 survey in four UK national longitudinal studies.

BACKGROUND: Key workers played a pivotal role during the national lockdown in the UK's response to the COVID-19 pandemic. Although protective measures have been taken, the impact of the pandemic on key workers is yet to be fully elucidated. METHODS: Participants were from four longitudinal age-homogeneous British cohorts (born in 2001, 1990, 1970 and 1958). A web-based survey provided outcome data during the first UK national lockdown (May 2020) on COVID-19 infection status, changes in financial situation, trust in government, conflict with people around, household composition, psychological distress, alcohol consumption, smoking and sleep duration. Generalised linear models with logit link assessed the association between being a key worker and the above outcomes. Adjustment was made for cohort design, non-response, sex, ethnicity, adult socioeconomic position (SEP), childhood SEP, the presence of a chronic illness and receipt of a shielding letter. Meta-analyses were performed across the cohorts. FINDINGS: 13 736 participants were included. During lockdown, being a key worker was associated with increased chances of being infected with COVID-19 (OR 1.43, 95% CI 1.22 to 1.68) and experiencing conflict with people around (OR 1.19, 95% CI 1.03 to 1.37). However, key workers were less likely to be worse off financially (OR 0.32, 95% CI 0.24 to 0.65), to consume more alcohol (OR 0.88, 95% CI 0.79 to 0.98) or to smoke more (OR 0.60, 95% CI 0.44 to 0.80) during lockdown. Interestingly, being a key worker was not associated with psychological distress (OR 0.95, 95% CI 0.85 to 1.05). INTERPRETATION: Being a key worker during the first UK COVID-19 lockdown was a double-edged sword, with both benefits and downsides. The UK government had the basic duty to protect its key workers from SARS-CoV-2 infection, but it may have failed to do so, and there is an urgent need to rectify this in light of the ongoing third wave.

Evaluating access to health and care services during lockdown by the COVID-19 survey in five UK national longitudinal studies.

OBJECTIVE: Access to health services and adequate care is influenced by sex, ethnicity, socioeconomic position (SEP) and the burden of comorbidities. Our study aimed to assess whether the COVID-19 pandemic further deepened these already existing health inequalities. DESIGN: Cross-sectional study. SETTING: Data were collected from five longitudinal age-homogenous British cohorts (born in 2000-2002, 1989-1990, 1970, 1958 and 1946). PARTICIPANTS: A web survey was sent to the cohorts. Anybody who responded to the survey was included, resulting in 14 891 eligible participants. MAIN OUTCOMES MEASURED: The survey provided data on cancelled surgical or medical appointments, and the number of care hours received in a week during the first UK COVID-19 national lockdown. INTERVENTIONS: Using binary or ordered logistic regression, we evaluated whether these outcomes differed by sex, ethnicity, SEP and having a chronic illness. Adjustment was made for study design, non-response weights, psychological distress, presence of children or adolescents in the household, COVID-19 infection, key worker status, and whether participants had received a shielding letter. Meta-analyses were performed across the cohorts, and meta-regression was used to evaluate the effect of age as a moderator. RESULTS: Women (OR 1.40, 95% CI 1.27 to 1.55) and those with a chronic illness (OR 1.84, 95% CI 1.65 to 2.05) experienced significantly more cancellations during lockdown (all p<0.0001). Ethnic minorities and those with a chronic illness required a higher number of care hours during the lockdown (both OR≈2.00, all p<0.002). SEP was not associated with cancellation or care hours. Age was not independently associated with either outcome in the meta-regression. CONCLUSION: The UK government's lockdown approach during the COVID-19 pandemic appears to have deepened existing health inequalities, impacting predominantly women, ethnic minorities and those with chronic illnesses. Public health authorities need to implement urgent policies to ensure equitable access to health and care for all in preparation for a fourthwave.

The effects of home visiting on mother-child interactions: Evidence from a randomized trial using dynamic micro-level data.

BACKGROUND: Home visiting programs constitute an important policy to support vulnerable families with young children. One of their principal aims is to improve infant-parent relationships, so a key measure of their effectiveness is based on observational measures of parent-children interactions. In the present study we provide novel evidence on the effectiveness of home visiting programs in improving mother-child interactions within a randomized controlled trial (RCT) of the Pro Kind program. A major goal of the Pro Kind program is to promote child development by strengthening the intuitive parenting skills of mothers. On this basis, the following research question is addressed in this paper: What is the impact of the Pro Kind home visitation program on the quality of mother-child interaction? METHODS: A randomly chosen subsample of the original sample was selected to participate on video recordings. This subsample of 109 mother-child dyads was videotaped during a 3-min typical play situation at the participants' homes when the child was aged 25 months. We use a novel micro-coding system which allows us to examine how the intervention affected the dynamic feedback responses of both mothers and children in three key measures of behavior: orientation, positive contingency, and negative/lack of contingency. The analysis was conducted using a set of static probit models and dynamic cross-lagged panel probit models for each measure. RESULTS: The intervention significantly improved the interactions between girls and their mothers, by increasing the prevalence of orientation and positive contingency (and reducing that of negative/lack of contingency). This was achieved by increasing both the persistence of positive behaviors and also the probability of switching from negative to positive behaviors in the treatment group. Mixed impacts were detected for boys. CONCLUSIONS: Overall, it can be said that the Pro Kind program has a positive impact on the quality of mother-daughter interaction. However, our findings might also influence the design and delivery of home visiting programs, to the extent that they suggest that more attention has to be devoted to the interactions between boys and their mothers. Furthermore, the results show the importance of careful dynamic modelling of interactions data from videotaped observations to have a more complete understanding of the effectiveness of home visiting programs.

Influence of childhood socioeconomic position and ability on mid-life cognitive function: evidence from three British birth cohorts.

BACKGROUND: Childhood socioeconomic position (SEP) is robustly associated with cognitive function later in life. However, it is unclear whether this reflects a direct relationship, or an indirect association via modifiable factors such as educational attainment and occupation. We sought to clarify these associations using retrospectively harmonised data from three ongoing British birth cohorts. METHODS: We analysed data from the 1946 National Survey of Health and Development (n=2283), the 1958 National Child Development Study (n=9385) and the 1970 British Cohort Study (n=7631). Retrospective harmonisation was used to derive equivalent indicators of cognition, SEP, education and occupation across the three cohorts. Structural equation modelling was used to examine the association between childhood SEP and mid-life cognitive function, via childhood cognitive ability, educational attainment and mid-life occupation. RESULTS: Across all three cohorts, no direct pathways were observed between childhood SEP and mid-life cognitive function. Rather, this association was indirect via the three temporally ordered mediators. In addition, the direct pathway between childhood cognition and adult cognitive function was weaker in the two younger studies. CONCLUSIONS: Across three British birth cohorts, we found that the association between early life SEP and mid-life cognitive function was fully mediated by childhood cognitive ability, educational attainment and occupational status. Furthermore, the association between early cognitive ability and mid-life cognitive function has decreased in younger generations. Therefore, cognitive function in adulthood may be influenced by modifiable factors and societal change.

A Demonstration Study of the Quiet Time Transcendental Meditation Program.

This manuscript presents a demonstration study of Quiet Time (QT), a classroom-based Transcendental Meditation intervention. The aim of the study is to assess the feasibility of implementing and evaluating QT in two pilot settings in the United Kingdom and Ireland. This study contributes to the field by targeting middle childhood, testing efficiency in two settings operating under different educational systems, and including a large array of measures. First, teacher and pupil engagement with QT was assessed. Second, the feasibility of using a quasi-experimental design and a wide range of instruments to measure changes in pupil outcomes before and after the intervention was assessed. This allows us to obtain information about which instruments might be feasible to administer and most sensitive to change. The first setting included 89 students from a primary school in the United Kingdom: those in sixth grade received the QT intervention, while those in fifth grade practiced meditation using the Headspace application. The second setting included 100 fifth- and sixth-grade students from two schools in Ireland: one received the QT intervention, the other served as a control. Recruitment and retention rates were high in both settings, and the intervention was feasible and accepted by students, parents and teachers. Implementation fidelity was lower in the United Kingdom setting where delivery started later in the school year and the practice was affected by preparation for the Standard Assessment Tests. These results show that QT may be feasibly delivered in school settings, and suggest the use of a compact battery of tests to measure impact. We find suggestive evidence that the intervention affected executive function as children who practiced QT showed improved working memory in both settings. In the Irish setting, pupils in the QT group had improved ability to control responses. These results have implications for future studies by a) demonstrating that implementation fidelity is highly context dependent and b) providing suggestive evidence of the malleability of children's skills in middle childhood. The results of this demonstration study will be used to inform a larger RCT of the QT intervention.

Building resilient societies after COVID-19: the case for investing in maternal, neonatal, and child health.

Resilient societies respond rapidly and effectively to health challenges and the associated economic consequences, and adapt to be more responsive to future challenges. Although it is only possible to recognise resilience retrospectively, the COVID-19 pandemic has occurred at a point in human history when, uniquely, sufficient knowledge is available on the early-life determinants of health to indicate clearly that a focus on maternal, neonatal, and child health (MNCH) will promote later resilience. This knowledge offers an unprecedented opportunity to disrupt entrenched strategies and to reinvest in MNCH in the post-COVID-19 so-called new normal. Furthermore, analysis of the short-term, medium-term, and longer-term consequences of previous socioeconomic shocks provides important insights into those domains of MNCH, such as neurocognitive development and nutrition, for which investment will generate the greatest benefit. Such considerations apply to high-income countries (HICs) and low-income and middle-income countries (LMICs). However, implementing appropriate policies in the post-COVID-19 recovery period will be challenging and requires political commitment and public engagement.

Inequality in socio-emotional skills: A cross-cohort comparison.

We examine changes in inequality in socio-emotional skills very early in life in two British cohorts born 30 years apart. We construct comparable scales using two validated instruments for the measurement of child behaviour and identify two dimensions of socio-emotional skills: 'internalising' and 'externalising'. Using recent methodological advances in factor analysis, we establish comparability in the inequality of these early skills across cohorts, but not in their average level. We document for the first time that inequality in socio-emotional skills has increased across cohorts, especially for boys and at the bottom of the distribution. We also formally decompose the sources of the increase in inequality and find that compositional changes explain half of the rise in inequality in externalising skills. On the other hand, the increase in inequality in internalising skills seems entirely driven by changes in returns to background characteristics. Lastly, we document that socio-emotional skills measured at an earlier age than in most of the existing literature are significant predictors of health and health behaviours. Our results show the importance of formally testing comparability of measurements to study skills differences across groups, and in general point to the role of inequalities in the early years for the accumulation of health and human capital across the life course.

Prenatal and Infancy Nurse Home Visiting Effects on Mothers: 18-Year Follow-up of a Randomized Trial.

BACKGROUND: Prenatal and infancy home-visiting by nurses is promoted as a means of improving maternal life-course, but evidence of long-term effects is limited. We hypothesized that nurse-visitation would lead to long-term reductions in public-benefit costs, maternal substance abuse and depression, and that cost-savings would be greater for mothers with initially higher psychological resources. METHODS: We conducted an 18-year follow-up of 618 out of 742 low-income, primarily African-American mothers with no previous live births enrolled in an randomized clinical trial of prenatal and infancy home visiting by nurses. We compared nurse-visited and control-group women for public-benefit costs, rates of substance abuse and depression, and examined possible mediators of intervention effects. RESULTS: Nurse-visited women, compared with controls, incurred $17 310 less in public benefit costs (P = .03), an effect more pronounced for women with higher psychological resources ($28 847, P = .01). These savings compare with program costs of $12 578. There were no program effects on substance abuseor depression. Nurse-visited women were more likely to be married from child age 2 through 18 (19.2% vs 14.8%, P = .04), and those with higher psychological resources had 4.64 fewer cumulative years rearing subsequent children after the birth of the first child (P = .03). Pregnancy planning was a significant mediator of program effects on public benefit costs. CONCLUSIONS: Through child age 18, the program reduced public-benefit costs, an effect more pronounced for mothers with higher psychological resources and mediated by subsequent pregnancy planning. There were no effects on maternal substance abuse and depression.

Prenatal and Infancy Nurse Home Visiting and 18-Year Outcomes of a Randomized Trial.

OBJECTIVES: Given earlier effects found in randomized clinical trials of the Nurse-Family Partnership, we examined whether this program would improve 18-year-old first-born youths' cognition, academic achievement, and behavior and whether effects on cognitive-related outcomes would be greater for youth born to mothers with limited psychological resources (LPR) and on arrests and convictions among females. METHODS: We enrolled 742 pregnant, low-income women with no previous live births and randomly assigned them to receive either free transportation for prenatal care plus child development screening and referral (control; n = 514) or prenatal and infant home nurse visit (NV) plus transportation and screening (n = 228). Assessments were completed on 629 18-year-old first-born offspring to evaluate these primary outcomes: (1) cognitive-related abilities (nonverbal intelligence, receptive language, and math achievement) and (2) behavioral health (internalizing behavioral problems, substance use and abuse, sexually transmitted infections, HIV risk, arrests, convictions, and gang membership). RESULTS: Compared with control-group counterparts, NV youth born to mothers with LPR had better receptive language (effect size = 0.24; 95% confidence interval [CI]: 0.00 to 0.47; P = .05), math achievement (effect size = 0.38; 95% CI: 0.14 to 0.61; P = .002), and a number of secondary cognitive-related outcomes. NV females, as a trend, had fewer convictions (incidence ratio = 0.47; 95% CI: 0.20 to 1.11; P = .08). There were no intervention effects on other behaviors. CONCLUSIONS: The program improved the cognitive-related skills of 18-year-olds born to mothers with LPR and, as a trend, reduced female convictions but produced no other effects on youth behavioral health.

Preconception health in England: a proposal for annual reporting with core metrics.

There is growing interest in preconception health as a crucial period for influencing not only pregnancy outcomes, but also future maternal and child health, and prevention of long-term medical conditions. Successive national and international policy documents emphasise the need to improve preconception health, but resources and action have not followed through with these goals. We argue for a dual intervention strategy at both the public health level (eg, by improving the food environment) and at the individual level (eg, by better identification of those planning a pregnancy who would benefit from support to optimise health before conception) in order to raise awareness of preconception health and to normalise the notion of planning and preparing for pregnancy. Existing strategies that target common risks factors, such as obesity and smoking, should recognise the preconception period as one that offers special opportunity for intervention, based on evidence from life-course epidemiology, developmental (embryo) programming around the time of conception, and maternal motivation. To describe and monitor preconception health in England, we propose an annual report card using metrics from multiple routine data sources. Such a report card should serve to hold governments and other relevant agencies to account for delivering interventions to improve preconception health.

The Effects of Two Influential Early Childhood Interventions on Health and Healthy Behaviour.

This paper examines the long-term impacts on health and healthy behaviors of two of the oldest and most widely cited U.S. early childhood interventions evaluated by the method of randomization with long-term follow-up: the Perry Preschool Project (PPP) and the Carolina Abecedarian Project (ABC). There are pronounced gender effects strongly favoring boys, although there are also effects for girls. Dynamic mediation analyses show a significant role played by improved childhood traits, above and beyond the effects of experimentally enhanced adult socioeconomic status. These results show the potential of early life interventions for promoting health.

Early Health Shocks, Intra-household Resource Allocation and Child Outcomes.

An open question in the literature is whether families compensate or reinforce the impact of child health shocks. Discussions usually focus on one dimension of child investment. This paper examines multiple dimensions using household survey data on Chinese child twins whose average age is 11. We find that, compared with a twin sibling who did not suffer from negative early health shocks at ages 0-3, the other twin sibling who did suffer negative health shocks received RMB 305 more in terms of health investments, but received RMB 182 less in terms of educational investments in the 12 months prior to the survey. In terms of financial transfers over all dimensions of investment, the family acts as a net equalizer in response to early health shocks for children. We estimate a human capital production function and establish that, for this sample, early health shocks negatively affect child human capital, including health, education, and socioemotional skills. Compensating investments in health as measured by BMI reduce the adverse effects of health shocks by 50%, but exacerbate the adverse impact of shocks on educational attainment by 30%.