Earnings capacity forecasts typically utilize work-life estimates and life expectancy estimates that are based on population averages. In specific personal injury and wrongful death cases, such estimates should be modified by considering the plaintiff’s pre-incident health. Obesity is one health condition that should be considered when forecasting how long the plaintiff would have worked and lived had the incident not occurred.

Sources of life expectancy estimates include life tables from the Social Security Administration(SSA)^[i] for the general population, and the Center for Disease Control (CDC)^[ii] which includes a breakdown by race. The SSA further adds a calculator to determine life expectancy based on one’s gender and exact age.^[iii]

Work-life expectancy is a bit more controversial. Often, the plaintiff’s economist will assume a work-life to age 67 since that is the age at which full Social Security benefits can be received. The typical person, however, retires well before age 67. A standard reference for work-life expectancy are the tables provided by Kreuger and Slesnick.^[iv] These tables estimate work-life based on a person’s age, education, gender and current labor market status. 

The above-referenced sources are all based on the average person and are acceptable as-is to the extent that the plaintiff is an average person. Often, a plaintiff has characteristics that are not possessed by the average person, and, as such, these estimates need to be modified. One condition that can impact work-life expectancy and life expectancy is obesity.

Measures of obesity and being overweight are determined by the body mass index (BMI).According the CDC^[v]:

BMI is a person’s weight in kilograms divided by the square of height in meters. A high BMI can indicate high body fatness.

• If your BMI is less than     18.5, it falls within the underweight range.
• If your BMI is 18.5 to     <25, it falls within the healthy weight range.
• If your BMI is 25.0 to     <30, it falls within the overweight range.
• If your BMI is 30.0 or     higher, it falls within the obesity range.

Obesity is frequently subdivided into categories:

• Class 1: BMI of 30 to < 35
• Class 2: BMI of 35 to < 40
• Class 3: BMI of 40 or higher.     Class 3 obesity is sometimes categorized as “severe” obesity.

Peeters, et al. (2003)^[vi] analyze the Framingham Heart Study with follow-up from 1948 to 1990 to estimate the impact of smoking and obesity on life expectancy. “Forty-year-old female nonsmokers lost 3.3 years and 40-year-old male nonsmokers lost 3.1 years of life expectancy because of overweight. Forty-year-old female nonsmokers lost 7.1 years and 40-year-old male nonsmokers lost 5.8 years because of obesity. Obese female smokers lost 7.2 years and obese male smokers lost 6.7 years of life expectancy compared with normal-weight smokers. Obese female smokers lost 13.3 years and obese male smokers lost 13.7 years compared with normal-weight nonsmokers.”

Houston, Cai and Stevens (2012)^[vii] “examine associations between weight status in young and middle age and early retirement” employing data from the Atherosclerosis Risk in Communities (ARIC)study. They define early retirement as retiring before age 65, and they also test for retirement before age 62 years. “Among white men, being overweight or obese in young adulthood and obese in middle adulthood was associated with early retirement. Being overweight or obese in young adulthood was also associated with early retirement in African-American men and women. Overweight or obesity in young or middle age was not associated with early retirement in white women.”

To conclude, forensic economists should consider the plaintiff’s pre-incident health when estimating pre-incident earnings capacity. Obesity can reduce life expectancy and work-life expectancy. Further, smoking can compound the impact of obesity.

^[i] https://www.ssa.gov/oact/STATS/table4c6.html

^[ii] https://www.cdc.gov/nchs/products/life_tables.htm#life

^[iii] https://www.ssa.gov/oact/population/longevity.html

^[iv] Kurt V. Krueger and Frank Slesnick, “Total WorklifeExpectancy,” Journal of Forensic Economics, 25(1) 2014, pp. 51-70.

^[v] https://www.cdc.gov/obesity/index.html

^[vi] https://www.acpjournals.org/doi/abs/10.7326/0003-4819-138-1-200301070-00008

^[vii] https://onlinelibrary.wiley.com/doi/full/10.1038/oby.2008.464