The economics of aging with infectious and chronic diseases.

We develop an economic model of aging in which the susceptibility and severity of infectious diseases depend on the accumulated health deficits (immunosenescence) and the life history of infections affects the accumulation of chronic health deficits (inflammaging). Individuals invest in their health to slow down health deficit accumulation and take measures to protect themselves from infectious diseases. We calibrate the model for an average American and explore how health expenditure, life expectancy, and the value of life depend on individual characteristics, medical technology, and the disease environment. We then use counterfactual computational experiments of the U.S. epidemiological transition 1860-2010 to show that the decline of infectious diseases caused a substantial decline of chronic diseases and contributed more to increasing life expectancy than advances in the treatment of chronic diseases.

Physiological aging and life-cycle labor supply across countries.

We construct a cohort-based frailty index for 180 countries over the period 1990-2019. We use this measure of physiological aging to estimate the impact of deteriorating health on labor force participation. Our three-dimensional panel framework, in which the unit of observation is a cohort in a given country at a given age, allows us to control for a range of unobserved factors. Our identification strategy further exploits a compensating law of physiological aging to account for reverse causality. We find a negative effect of physiological aging on labor market participation: an increase of the frailty index by one percent leads to a reduction of labor force participation of about 0.6 (±0.2) percentage points. Since health deficits (in the frailty index) are accumulated at a rate of about 3 percent per year of life, almost all of the age-related decline in labor force participation can be motivated by deteriorating health.

Physiological aging in India: The role of the epidemiological transition.

We construct a cohort-based frailty index from age-related health deficits to investigate physiological aging in India over the period 1990-2019. During this period, the Indian states underwent at different speeds the epidemiological transition and experienced unprecedented economic growth. We show that the rate of physiological aging remained remarkably stable to the changing environment. Age-related health deficits increased by about 3 percent per year of age with little variation across states, ages, cohorts, and over time. We find that, with advancing epidemiological transition, health deficits for given age declined at the individual level (within states and within cohorts). Across cohorts born between 1900 and 1995, we show that, for given age, health deficits are higher for later-born cohorts until birth years around 1940 and remained trendless afterwards. We propose a selection-based theory of aging during the epidemiological transition that explains these facts.

Anticipation of deteriorating health and information avoidance.

We integrate anticipatory utility and endogenous beliefs about future negative health shocks into a life-cycle model of physiological aging. Individuals care about their future utility derived from their health status and form endogenous beliefs about the probability of a negative health shock. We calibrate the model with data from gerontology and use the model to predict medical testing decisions of individuals. We find that anticipation in combination with endogenous beliefs provides a quantitatively strong motive to avoid medical testing for Huntington's disease, which explains the low testing rates found empirically. We also study the case of breast and ovarian cancer and provide an explanation for why testing rates depend on the individual's income when treatment is available.

Hooked on weight control: An economic theory of anorexia nervosa and its impact on health and longevity.

In this paper, I integrate a theory of body image, weight control, and addiction in a life cycle model with health deficit accumulation in order to explain the phenomenon of anorexia nervosa and its impact on health and longevity. Individuals consume normal goods and foods and can work off excess calories with physical exercise. There exists a healthy body mass index and deviations from it increasingly cause health deficits due to obesity or underweight. There exists also a subjective target weight and being heavier than target weight causes a loss of utility from body image. Anorexia is initiated in individuals who are particularly successful in weight control and prone to addiction. Addiction to weight control motivates anorexic individuals to perpetually adjust their target weight downwards and to eat less and exercise more. With declining weight, health deficits accumulate faster and mortality risk rises. I calibrate the model to an average American woman with bmi 28. Due to weight loss addiction, the bmi declines to a level of 15 and causes an expected loss of 15 years of life. I also discuss potential therapies and recovery from the disease.

Physiological aging around the World.

We extract data on physiological aging by computing a frailty index for 201 countries over the period 1990-2019. Using panel estimation techniques, we show that the macro frailty index replicates basic regularities previously observed in related studies of aging at the individual level. We then use the frailty index to highlight trends of global physiological aging and its relationship to economic growth. Holding population age structure fixed, the global frailty index has on average increased by about 2 percent over the last 30 years. The average person has therefore aged by what corresponds to about one life-year of physiological aging. This overall trend is relatively similar across different geographical regions. We also document a negative relationship between physiological aging of the workforce and economic growth. According to our preferred specification, a one percent increase in the frailty index of the workforce is associated with a 1.5 percent decline of GDP per capita. This means that average annual growth of labor productivity would have been 0.1 percentage points higher without physiological aging in the period 1990-2019.

A health economic theory of occupational choice, aging, and longevity.

In this paper, I propose a life cycle model of occupational choice with endogenous health behavior, aging, and longevity. Health-demanding work leads to a faster accumulation of health deficits and is remunerated with a hazard markup on wages. Health deficit accumulation is also influenced by unhealthy consumption and health care expenditure. I calibrate the model for a 20 year old average American in 2010 and show the following results, among others. Health-demanding work is ceteris paribus preferred by male, young, and healthy individuals with a relatively low level of education. Health demanding work has a negligible effect on health behavior because income and health investment effects largely offset each other, implying that health effects can be attributed almost fully to the direct health burden of work. Better medical technology induces low-skilled individuals to spend a greater part of their life in health-demanding work and thus increases the health gradient of education. High wealth endowments protect against unhealthy occupational choices. I show robustness of the results in an extension of the model with regard to endogenous retirement.

The impact of menstruation hygiene management on work absenteeism of women in Burkina Faso.

Women in developing countries face challenges in terms of managing their menstrual hygiene. They often do not possess the appropriate means, materials, or have access to suitable facilities. Using a newly released dataset for Burkina Faso and propensity score matching, we provide for the first time evidence of the impact of advanced menstrual hygiene management on work attendance. We show that the use of disposable sanitary pads rather than old cloth reduces work absenteeism of women by approximately 24% points. We report the robustness of the results with respect to alternative specifications of the propensity score model and investigate the results for samples stratified by education, wealth, marital status, and religion.

Social vulnerability and aging of elderly people in the United States.

We use 7 waves of the Health and Retirement Study and construct a social vulnerability index (SVI) for elderly U.S. Americans (born 1913-1966). We show that the SVI is mildly larger for men than for women and increases in age from above age 60 onwards for both genders. Social vulnerability of men (but not of women) is lower in the West and Midwest than in other regions and higher income mildly reduces the SVI for men (but not for women). In cohort analysis we find an increase of the SVI for individuals born in the late 1940s or later, which is, however, statistically significant only for women. In order to investigate the nexus between social vulnerability and aging, we construct a frailty index from the same data. We find that socially vulnerable persons display more health deficits at any age. Using the initial SVI (at first interview) we find that social vulnerability exerts a significant impact on subsequent accumulation of health deficits, which is of about the same size for men and women. A one standard deviation increase in the initial SVI leads to a 20 percent increase of the frailty index at any age.

Fetal origins-A life cycle model of health and aging from conception to death.

The fetal origins hypothesis suggests that health and nutrition shocks in utero are causally related to health deficits in old age. It has received considerable empirical support, both within epidemiology and economics but so far it has not been integrated into a life cycle theory of human aging and longevity. The present study shows that the health deficit model, based on the frailty index developed in gerontology, generates shock amplification consistent with the hypothesis. In order to discuss human health over the life cycle from conception to death, we develop a theory of ontogenetic growth and health in utero and during childhood, unify it with the health deficit model of adult aging, and discuss the transmission of early-life shocks to late-life health deficit accumulation.

Time-inconsistent health behavior and its impact on aging and longevity.

We integrate time-inconsistent decision making due to hyperbolic discounting into a gerontologically founded life cycle model with endogenous aging and longevity. Individuals can slow down aging and postpone death by health investments and by reducing unhealthy consumption, conceptualized as smoking. We show that individuals continuously revise their original plans to smoke less and invest more in their health. Consequently, they accumulate health deficits faster and die earlier than originally planned. This fundamental health consequence of time-inconsistency has not been addressed in the literature so far. Because death is endogenous, any attempt to establish the time-consistent first-best solution by manipulating the first order conditions through (sin-) taxes and subsidies is bound to fail. We calibrate the model with U.S. data for an average American in the year 2012 and estimate that time-inconsistent health behavior causes a loss of about 4 years of life. We show how price policy can nudge individuals to behave more healthy such that they actually realize the longevity and value of life planned at age 20.

From pain patient to junkie: An economic theory of painkiller consumption and its impact on wellbeing and longevity.

In this paper, I propose a life cycle model of painkiller consumption that combines the theory of health deficit accumulation with the theory of addiction. Chronic pain is conceptualized as a persistent negative shock to lifetime utility that can be treated by pain relief medication. Individuals treated with opioid pain relievers (OPR) develop addiction, which increases their demand for opioids and reduces their welfare and life expectancy through side effects and potential overdose. I calibrate the model for a benchmark American and investigate the comparative dynamics of alternative drug characteristics, pain intensities, and ages of onsets of pain as well as their implications for welfare and life expectancy. Computational experiments are used to identify fully rational and imperfectly rational addiction behavior. Fully rational addicts reduce OPR use when new information about the addictive potential of these drugs arrives. Imperfectly rational addicts further develop their addiction and switch to illicit opioid use. Likewise, a discontinued prescription helps fully rational addicts to quit quickly, while it induces imperfectly rational individuals to take up heroin. I also discuss treatment of OPR addiction and the use of opioids in palliative care.

Aging in the USA: similarities and disparities across time and space.

We study biological aging of elderly U.S. Americans born 1904-1966. We use thirteen waves of the Health and Retirement Study and construct a frailty index as the number of health deficits present in a person measured relative to the number of potential deficits. We find that, on average, Americans develop 5% more health deficits per year, that men age slightly faster than women, and that, at any age above 50, Caucasians display significantly fewer health deficits than African Americans. We also document a steady time trend of health improvements. For each year of later birth, health deficits decline on average by about 1%. This health trend is about the same across regions and for men and women, but significantly lower for African Americans compared to Caucasians. In non-linear regressions, we find that regional differences in aging follow a particular regularity, akin to the compensation effect of mortality. Health deficits converge for men and women and across American regions and suggest a life span of the American population of about 97 years.

Opioid epidemics.

In this paper, I propose an economic theory that addresses the epidemic character of opioid epidemics. I consider a community in which individuals are heterogenous with respect to the experience of chronic pain and susceptibility to addiction and live through two periods. In the first period they consider whether to treat pain with opioid pain relievers (OPRs). In the second period they consider whether to continue non-medical opioid use to mitigate cravings from addiction. Non-medical opioid use is subject to social disapproval, which depends negatively on the share of opioid addicts in the community. An opioid epidemic is conceptualized as the transition from an equilibrium at which opioid use is low and addiction is highly stigmatized to an equilibrium at which opioid use is prevalent and social disapproval is low. I show how such a transition is initiated by the wrong belief that OPRs are not very addictive. Under certain conditions there exists an opioid trap such that the community persists at the equilibrium of high opioid use after the wrong belief is corrected. Refinements of the basic model consider the recreational use of prescription OPRs and an interaction between income, pain, and addiction.

Season of birth, health and aging.

We investigate how the season of birth is related to human health and aging. For this purpose, we use five waves of the Survey of Health, Aging, and Retirement in Europe (SHARE) dataset and construct a health deficit index for 21 European countries. Results from log-linear regressions suggest that, on average, elderly European men age faster when they were born in spring and summer (compared to autumn). At any given age, they have developed about 3.5 percent more health deficits. These differences due to seasons of birth are not mediated by body height and education. In a subsample of Southern European countries, where the seasonal variation of sunlight is smaller, the birth season plays an insignificant role for health in old age. In a subsample of Northern countries, in contrast, the season of birth coefficients increase. At any given age, elderly Northern European men born in spring have developed, on average, 8.7 percent more health deficits than those born in autumn. In non-linear regressions we find that the speed of aging is also associated with the birth season.

Limited self-control and longevity.

This paper proposes a new framework to discuss self-control problems in the context of life-cycle health and longevity. Individual decisions are conceptualized as the partial control of impulsive desires of a short-run self by a rationally forward-looking long-run self. The short-run self strives for immediate gratification through consumption of health-neutral and unhealthy goods. The long-run self reflects the long-term consequences of unhealthy behavior on health outcomes and longevity and invests time and money to improve current and future health. The model is calibrated with data from the United States and used to provide an assessment of the impact of imperfect self-control on unhealthy consumption, health investments, lifetime health, and the age at death.

Smoking kills: An economic theory of addiction, health deficit accumulation, and longevity.

In this paper I unify the economic theories of addiction and health deficit accumulation and develop a life cycle theory in which individuals take into account the fact that the consumption of addictive goods reduces their health and longevity. I distinguish two types of addiction: sophisticated and naive. Individuals with sophisticated addiction perfectly control their addiction. Individuals with naive addiction, though otherwise rational and forward looking, fail to fully understand how their addiction develops. I argue that the life cycle consumption pattern predicted for naive addiction is more suitable for motivating empirically observable patterns of addictive goods consumption. I take the case of smoking as unhealthy behavior, calibrate the model with U.S. data, and apply it in order to investigate the life cycle patterns of smoking and quitting smoking and the socioeconomic gradients of unhealthy consumption and longevity.

Hungry children age faster.

We analyze how childhood hunger affects human aging for a panel of European individuals. For this purpose, we use six waves of the Survey of Health, Aging, and Retirement in Europe (SHARE) dataset and construct a health deficit index. Results from log-linear regressions suggest that, on average, elderly European men and women developed about 20 percent more health deficits when they experienced a hunger episode in their childhood. The effect becomes larger when the hunger episode is experienced earlier in childhood. In non-linear regressions (akin to the Gompertz-Makeham law), we obtain greater effects suggesting that health deficits in old age are up to 40 percent higher for children suffering from hunger. The difference of health deficits between hungry and non-hungry individuals increases absolutely and relatively with age. This implies that individuals who suffered from hunger as children age faster.

How We Fall Apart: Similarities of Human Aging in 10 European Countries.

We analyze human aging-understood as health deficit accumulation-for a panel of European individuals, using four waves of the Survey of Health, Aging and Retirement in Europe (SHARE data set) and constructing a health deficit index. Results from log-linear regressions suggest that, on average, elderly European men and women develop approximately 2.5 % more health deficits from one birthday to the next. In nonlinear regressions (akin to the Gompertz-Makeham model), however, we find much greater rates of aging and large differences between men and women as well as between countries. Interestingly, these differences follow a particular regularity (akin to the compensation effect of mortality) and suggest an age at which average health deficits converge for men and women and across countries. This age, which may be associated with human life span, is estimated as 102 ± 2.6 years.

The gender gap in mortality: How much is explained by behavior?

In developed countries, women are expected to live about 4-5 years longer than men. In this paper, we develop a novel approach to gauge the extent to which gender differences in longevity can be attributed to gender-specific preferences and health behavior. We set up a physiologically founded model of health deficit accumulation and calibrate it using recent insights from gerontology. From fitting life cycle health expenditure and life expectancy, we obtain estimates of the gender-specific preference parameters. We then perform the counterfactual experiment of endowing women with the preferences of men. In our benchmark scenario, this reduces the gender gap in life expectancy from 4.6 to 1.4 years. When we add gender-specific preferences for unhealthy consumption, the model can motivate up to 89 percent of the gender gap. Our theory offers also an economic explanation for why the gender gap declines with rising income.