Rising incomes, rising weights: causal evidence on economic mobility and overweight risk in Indonesia

Does economic progress come at the cost of population health? Using three waves (2000, 2007, 2014) of the Indonesia Family Life Survey and a Bartik-style shift-share instrumental variable that exploits exogenous regional sectoral growth, we identify the causal effect of upward economic mobility – transitions across expenditure-based strata – on overweight risk. We focus on upward mobility because structural transformation predominantly generates sustained income gains rather than reversals, and because the behavioural channels linking income growth to dietary change operate asymmetrically. IV estimates show that upward mobility increases body weight by 3.7–5.7 kg. Among individuals initially at normal weight, upward mobility raises the probability of becoming overweight by 18–63% points (p.p.); among those already overweight, it raises the probability of remaining overweight by 48–100 p.p. Additional descriptive analyses identify changes in diet, occupation, and physical activity as plausible behavioural pathways. These findings reveal a health cost embedded in economic success and call for nutrition-sensitive policies that accompany income-support programmes throughout the structural transformation process.