The allometry of metabolism and stature: Worker fatigue and height in the Tanzanian labor market

- In a sample of Tanzanian workers, this paper considers if the wage-height relationship is partly biological in origin.
- If metabolism scales proportionately with stature, taller individuals produce more energy for given work tasks.
- We find that the likelihood of being tired at the end-of-the workday varies inversely with height.
- Our results suggest that productivity increases with height as work-related fatigue is inversely related to worker stature.

If the positive wage-height correlation is at least partially biological in origin, one plausible pathway is the effect of stature on energy expenditure in individuals. If metabolism scales proportionately with stature, then relative to short individuals, taller individuals can produce more energy for a given work task. This also suggests that end-of-the-workday fatigue, or lack of energy, varies inversely with stature. We test this hypothesis with data from the 2004 Tanzanian Household Worker Survey in which workers report the extent of their fatigue at the end-of-the-workday. Ordinal latent variable parameter estimates reveal that relative to short workers, taller workers are less likely to report being tired at the end-of-the-workday. This suggests that the positive wage-height relationship also has a biological foundation whereby the energy requirements and metabolic costs associated with work effort/tasks are inversely related to stature.