Re-visiting the Health Care Luxury Good Hypothesis: Aggregation, Precision, and Publication Biases?

While a growing literature examining the relationship between income and health expenditures suggests that health care is a luxury good, this conclusion is contentiously debated due to heterogeneity of the existing results. This paper tests the luxury good hypothesis (namely that income elasticity exceed unity) using meta-regression analysis, taking into consideration publication selection and aggregation bias. The findings suggest that publication bias exists, a result that is robust to the meta-regression model employed. Publication selection and aggregation bias also appear to play a role in the generation of estimates. The corrected income elasticity estimates range from 0.4 to 0.8, which cast serious doubt on the validity of luxury good hypothesis. Nonetheless, due to the importance of aggregation, we cannot reject the luxury good hypothesis for aggregate time series data.