How well targeted are soda taxes?

Soda taxes aim to reduce externalities (including costs to the consumer themselves in the future) from excess sugar consumption. Their effectiveness depends on how consumers respond, and crucially how demand responsiveness correlates with marginal harm. We estimate demand using novel longitudinal data, which allows us to identify individual preference parameters. We study demand for drinks on-the-go, i.e. for immediate consumption. We show that heavy sugar consumers are the least willing to switch away from sugar in drinks, and that sugar taxes are regressive.