Impact of First Occupation on Health at Older Ages

Occupation is discussed as a social determinant of health. Occupation has received little attention in this light in the economics literature. We examine occupation in a life-course framework and use measures of first-occupation, initial health, and mother’s education. We contend that first occupation is a choice made relatively early in life that affects health outcomes at later ages. We examine first-occupation for two reasons: 1) there is growing evidence that early determinants affect later health and occupation has received little attention in this regard and 2) first occupation is predetermined in analysis of later health, which helps to address the issue of potential simultaneity. Using data from the Panel Study of Income Dynamics (PSID) we estimate the impact of initial occupation on two measures of health later in life: respondent-reported fair/poor health and ever suffering a heart attack. The PSID offers the opportunity to examine a lifecycle perspective as we can examine the impact of early occupation on later health while controlling for several predetermined conditions such as mother’s education and health in youth. Estimates suggest that first-occupation has a durable impact on later health, ceteris paribus, but that the impact varies by health measure and the set of control variables in regression specifications. Early choice of occupation could be a critical factor in successful aging and this information may pave the way to developing more effective workplace and public policies to improve health in older ages.

Work Expectations, Realizations, and Depression in Older Workers

We explore the impact on depressive symptoms of deviation in actual labor force behavior at age 62 from earlier expectations. Our sample of 4,241 observations is drawn from the Health and Retirement Study (HRS). We examine workers who were less than 62 years of age at the 1992 HRS baseline, and who had reached age 62 by our study endpoint, enabling comparison of actual labor force withdrawal with earlier expectations. Poisson regression were used to estimate the impact of expected full-time work status on depressive symptoms; regressions are estimated separately for those working fulltime at age 62 and those not working fulltime. We found significant effects on depression at age 62 both for full-time workers who expected not to be working full-time, and for participants not working full-time who expected to be doing so. These results hold even after adjustment for earlier depressive symptoms, sociodemographic and other relevant controls. The findings suggest that working longer and retiring earlier than expected each may compromise psychological well-being. The current financial crisis may result in both scenarios as some workers may have to work longer than expected due to the decline in pension and other wealth while others may retire earlier due to job loss.

Job Loss: Eat, Drink and Try to be Merry

Preliminary draft. Please do not quote. This paper examines the impact of job loss due to business closings on body mass index (BMI) and alcohol consumption. We suggest that the ambiguous findings in the extant literature may be due in part to unobserved heterogeneity in response and in part due to an overly broad measure of job loss that is partially endogenous (e.g. layoffs). We improve upon this literature by using: exogenously determined business closings, a sophisticated estimation approach (finite mixture models) to deal with complex heterogeneity, and national, longitudinal data from the Health and Retirement Study. For both alcohol consumption and BMI, we find evidence that individuals who are more likely to respond to job loss by increasing unhealthy behaviors are already in the problematic range for these behaviors before losing their jobs. These results suggest the health effects of job loss could be concentrated among “at risk ” individuals and could lead to negative outcomes for the individuals, their families, and society at large

The Impact of Early Occupational Choice On Health Behaviors

Occupational choice is a significant input into individuals’ health investments, operating in a manner that can be either health-promoting or health-depreciating. Recent studies have highlighted the potential importance of initial occupational choice on subsequent outcomes pertaining to morbidity. This study is the first to assess the existence and strength of a causal relationship between initial occupational choice at labor entry and subsequent health behaviors and habits. We utilize the Panel Study of Income Dynamics to analyze the effect of first occupation, as identified by industry category and blue collar work, on subsequent health outcomes relating to body mass index, obesity, alcohol consumption, and physical activity in 1999-2005. Our findings suggest that initial occupations described as craft, operative, and service are related to higher body mass index and obesity later in life, while labor occupations are related to higher probabilities of smoking later in life. Blue collar work early in life is associated with increased probabilities of obesity and smoking, and decreased physical activity later in life, although effects may be masked by unobserved heterogeneity. Few effects are found for the effect of initial occupation on alcohol consumption. The weight of the evidence bearing from various methodologies, which account for non-random unobserved selection, indicates that at least part of this effect is consistent with a causal interpretation. These estimates also underscore the potential durable impact of early labor market experiences on later health.

Sin Taxes: Do Heterogeneous Responses Undercut Their Value?

This paper estimates the price elasticity of demand for alcohol using Health and Retirement Survey data. To account for unobserved heterogeneity in price responsiveness, we use finite mixture models. We recover two latent groups, one is significantly responsive to price but the other is unresponsive. Differences between these two groups can be explained in part by the behavioral factors of risk aversion, financial planning horizon, forward looking and locus of control. These results have policy implications. Only a subgroup responds significantly to price. Importantly, the unresponsive group drinks more heavily, suggesting that a higher price could fail to curb drinking by those most likely to cause negative externalities. In contrast, those least likely to impose costs on others are more responsive, thus suffering greater deadweight loss yet with less prevention of negative externalities.

Job Loss: Eat, drink and try to be merry?

This paper examines the impact of job loss from business closings on body mass index (BMI) and alcohol consumption. We improve upon extant literature by using: exogenously determined business closings, a sophisticated estimation approach (finite mixture models) to deal with complex heterogeneity, and national, longitudinal data (Health and Retirement Study). For both alcohol consumption and BMI, we find evidence that individuals who are more likely to respond to job loss by increasing unhealthy behaviors are already in the problematic range for these behaviors before losing their jobs. Thus health effects of job loss could be concentrated among “at risk” individuals.

Effect of Loading Configuration on Kinematics and Kinetics for Deadlift and Squat Exercises: Case Study in Modeling Exercise Countermeasure Device for Astronauts

This study compares squat and deadlift exercises performed with two different loading configurations: 1) on a novel single-cable resistance exercise countermeasure device (ECD) for spaceflight and 2) with free weights. The results compare joint kinematics and kinetics between different loading configurations for each exercise, and also between the two exercises for each loading configuration. Single-cable versions of the squat (using a harness) and deadlift (using a T-bar) performed on the Hybrid Ultimate Lifting Kit (HULK) ECD have significantly different sagittal plane joint angle kinematics (both peak angle and range of motion) as well as joint kinetics (both peak joint moment and joint impulse) vs. their free weight equivalents at the same load. Differences also exist in hip abduction and rotation. Overall, the single-cable configurations tend to reduce peak joint angles, ranges of motion, peak joint moment and joint impulse vs. free weights. A notable exception is the lumbar joint, which is more heavily loaded for single-cable squats vs. free weight squats. This may have implications for both training benefit and possible risk of injury. Deadlift and squat exercises work the lower body musculature in different ways, with the deadlift emphasizing hip and lumbar extension and the squat emphasizing knee extension. Based on these findings, we would advocate the use of both movements in the exercise prescriptions of astronaut crews on deep-space missions

Estimation of Lower-Body Kinetics from Loading Profile and Kinematics Alone, Without Measured Ground Reaction Forces

Biomechanical models of human motion can estimate kinetic outcomes, such as joint moments, joint forces and muscle forces. Typically, one performs an inverse dynamics (ID) analysis to compute joint moments from joint angles and measured external forces. Sometimes it is impractical to measure ground reaction forces and moments (GRF&M). We devised an empirical method for performing ID analysis of resistance exercises without measured GRF&M. The method solves the multibody dynamics equations of motion with four key assumptions about the GRF&M that reduce the number of unknowns. The assumptions are 1) negligible ground reaction moments, 2) fixed lateral/medial location of the center of pressure (COP), 3) equal fore/aft location of the COP between the feet, and 4) constant angle of the GRF vector relative to the vertical axis in the frontal plane. We used evaluation trials from a spaceflight countermeasure resistance training device to test this approach. Four participants performed squat and deadlift exercises at various loads. We compared results from traditional ID analysis to results without measured GRF&M using our method. We found that joint moment trajectories in the sagittal plane were qualitatively similar in shape between the two methods, and the amount of root mean squared error (RMSE), measured by difference in joint moment impulse, was typically under 10 percent. Non-sagittal joint moment trajectories, which are much lower in overall magnitude, were not qualitatively similar in shape between the two methods. Non-sagittal moments displayed much higher RMSE, with typical values well over 50 percent. These findings were further supported by validation metrics (Sprague and Geers' P and M metrics, Pearson's r correlation coefficient). Based on these findings, we concluded that useful kinetic results are obtained from ID analysis of squat and deadlift exercises, even when GRF&M are not measured, as long as the outcomes of interest lie in the sagittal plane

Digital Astronaut Project Biomechanical Models: Biomechanical Modeling of Squat, Single-Leg Squat and Heel Raise Exercises on the Hybrid Ultimate Lifting Kit (HULK)

The NASA Digital Astronaut Project (DAP) implements well-vetted computational models to predict and assess spaceflight health and performance risks, and to enhance countermeasure development. The DAP Musculoskeletal Modeling effort is developing computational models to inform exercise countermeasure development and to predict physical performance capabilities after a length of time in space. For example, integrated exercise device-biomechanical models can determine localized loading, which will be used as input to muscle and bone adaptation models to estimate the effectiveness of the exercise countermeasure. In addition, simulations of mission tasks can be used to estimate the astronaut's ability to perform the task after exposure to microgravity and after using various exercise countermeasures. The software package OpenSim (Stanford University, Palo Alto, CA) (Ref. 1) is being used to create the DAP biomechanical models and its built-in muscle model is the starting point for the DAP muscle model. During Exploration missions, such as those to asteroids and Mars, astronauts will be exposed to reduced gravity for extended periods. Therefore, the crew must have access to exercise countermeasures that can maintain their musculoskeletal and aerobic health. Exploration vehicles may have very limited volume and power available to accommodate such capabilities, even more so than the International Space Station (ISS). The exercise devices flown on Exploration missions must be designed to provide sufficient load during the performance of various resistance and aerobic/anaerobic exercises while meeting potential additional requirements of limited mass, volume and power. Given that it is not practical to manufacture and test (ground, analog and/or flight) all candidate devices, nor is it always possible to obtain data such as localized muscle and bone loading empirically, computational modeling can estimate the localized loading during various exercise modalities performed on a given device to help formulate exercise prescriptions and other operational considerations. With this in mind, NASA's Digital Astronaut Project (DAP) is supporting the Advanced Exercise Concepts (AEC) Project, Exercise Physiology and Countermeasures (ExPC) laboratory and NSBRI-funded researchers by developing and implementing well-validated computational models of exercises with advanced exercise device concepts. This report focuses specifically on lower-body resistance exercises performed with the Hybrid Ultimate Lifting Kit (HULK) device as a deliverable to the AEC Project