Università di Bologna, Department of Economics, Piazza Scaravilli 2, 40126 Bologna, Italy.
J Health Econ. 2021 May;77:102452. doi: 10.1016/j.jhealeco.2021.102452. Epub 2021 Mar 19.
The milk addiction paradox refers to an empirical finding in which consumption of non-addictive commodities such as milk appears to be consistent with the theory of rational addiction. This paradoxical result seems more likely when consumption is persistent and with aggregate data. Using both simulated and real data, we show that the milk addiction paradox disappears when estimating the data using an AR(1) linear specification that describes the saddle-path solution of the rational addiction model, instead of the canonical AR(2) model. The AR(1) specification is able to correctly discriminate between rational addiction and simple persistence in the data, to test for the main features of rational addiction, and to produce unbiased estimates of the short and long-run elasticity of demand. These results hold both with individual and aggregated data, and they imply that the AR(1) model is a better empirical alternative for testing rational addiction than the canonical AR(2) model.
牛奶成瘾悖论是指一种经验性发现，即消费非成瘾性商品（如牛奶）似乎与理性成瘾理论一致。当消费是持续的并且使用汇总数据时，这种矛盾的结果似乎更有可能出现。使用模拟和真实数据，我们表明，当使用描述理性成瘾模型的鞍点解的 AR(1)线性规范来估计数据，而不是使用规范的 AR(2)模型时，牛奶成瘾悖论就会消失。AR(1)规范能够正确区分数据中的理性成瘾和简单持久性，检验理性成瘾的主要特征，并对短期和长期需求弹性进行无偏估计。这些结果既适用于个体数据，也适用于汇总数据，这意味着 AR(1)模型是比规范的 AR(2)模型更好的检验理性成瘾的经验替代方法。
