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We investigate how the coronavirus pandemic affected the demand for online food shopping services using data from the largest agri‐food e‐commerce platform in Taiwan. We find that an additional confirmed case of COVID‐19 increased sales by 5.7% and the number of customers by 4.9%. The demand for grains, fresh fruit and vegetables, and frozen foods increased the most, which benefited small farms over agribusinesses. The variety of products sold on the e‐commerce platform also increased during the pandemic, which suggests the concentration of sales on niche products could increase as more consumers are drawn to online platforms. Our investigation of mechanisms for the shift to online food shopping indicates that sales were highly responsive to COVID‐19 media coverage and online content.

To combat childhood overweight in the US, which has risen dramatically in the past three decades, many medical and public health organizations have called for students to spend more time in physical education (PE) classes. This paper is the first to examine the impact of state PE requirements on student PE exercise time. It also exploits variation in state laws as quasi-natural experiments in order to estimate the causal impact of PE on overall student physical activity and weight. We study nationwide data from the Youth Risk Behavior Surveillance System for 1999, 2001, and 2003 merged with data on state minimum PE requirements from the 2001 Shape of the Nation Report. We find that high school students with a binding PE requirement report an average of 31 additional minutes per week spent physically active in PE class. Our results also indicate that additional PE time raises the number of days per week that girls report having exercised vigorously or having engaged in strength-building activity. We find no evidence that PE lowers BMI or the probability that a student is overweight. We conclude that raising PE credit requirements may make girls more physically active overall but there is not yet the scientific base to declare raising PE requirements an anti-obesity initiative for either boys or girls.

This paper is the first to use the method of instrumental variables (IV) to estimate the impact of obesity on medical costs in order to address the endogeneity of weight and to reduce the bias from reporting error in weight. Models are estimated using data from the Medical Expenditure Panel Survey for 2000-2005. The IV model, which exploits genetic variation in weight as a natural experiment, yields estimates of the impact of obesity on medical costs that are considerably higher than the correlations reported in the previous literature. For example, obesity is associated with $676 higher annual medical care costs, but the IV results indicate that obesity raises annual medical costs by $2,826 (in 2005 dollars). The estimated annual cost of treating obesity in the U.S. adult non-institutionalized population is $168.4 billion or 16.5% of national spending on medical care. These results imply that the previous literature has underestimated the medical costs of obesity, resulting in underestimates of the cost effectiveness of anti-obesity interventions and the economic rationale for government intervention to reduce obesityrelated externalities.

BackgroundThe prevalence of obesity has more than doubled in the USA in the past 30 years. Obesity is a significant risk factor for diabetes, cardiovascular disease, and other clinically significant co-morbidities. This paper estimates the medical care cost savings that can be achieved from a given amount of weight loss by people with different starting values of body mass index (BMI), for those with and without diabetes. This information is an important input into analyses of the cost effectiveness of obesity treatments and prevention programs.MethodsTwo-part models of instrumental variables were estimated using data from the Medical Expenditure Panel Survey (MEPS) for 2000–2010. Models were estimated for all adults as well as separately for those with and without diabetes. We calculated the causal impact of changes in BMI on medical care expenditures, cost savings for specific changes in BMI (5, 10, 15, and 20 %) from starting BMI levels ranging from 30 to 45 kg/m2, as well as the total excess medical care expenditures caused by obesity.ResultsIn the USA, adult obesity raised annual medical care costs by $US3,508 per obese individual, for a nationwide total of $US315.8 billion (year 2010 values). However, the relationship of medical care costs over BMI is J-shaped; costs rise exponentially in the range of class 2 and 3 obesity (BMI ≥35). The heavier the obese individual, the greater the reduction in medical care costs associated with a given percent reduction in BMI. Medical care expenditures are higher, and rise more with BMI, among individuals with diabetes than among those without diabetes.ConclusionsThe savings from a given percent reduction in BMI are greater the heavier the obese individual, and are greater for those with diabetes than for those without diabetes. The results provide health insurers, employers, government agencies, and health economists with accurate estimates of the change in medical care expenditures resulting from weight loss, which is important information for calculating the cost effectiveness of interventions to prevent and treat obesity.Electronic supplementary materialThe online version of this article (doi:10.1007/s40273-014-0230-2) contains supplementary material, which is available to authorized users.