Instituto de Economia, Universidade Federal do Rio de Janeiro, Av. Pasteur 250, Urca, 22290-240, Rio de Janeiro, Brazil.
Eur J Health Econ. 2010 Aug;11(4):413-8. doi: 10.1007/s10198-010-0219-5. Epub 2010 Feb 10.
This paper tests for the existence of adverse selection in the Brazilian individual health insurance market in 2003. The testing approach adapts that conceived by Chiappori and Salanié (Eur Econ Rev 41, 943-950, 1997; J Polit Econ 108, 56-78, 2000). After controlling for sex, age, income, number of dependents, occupational groups and schooling levels, the evidence favors adverse selection as indicated by a positive correlation between the coverage of the contract and occurrence of illnesses (as approximated by hospitalization) was not strong. The consideration of complex sampling in the probit estimations led to empirical evidence that does not indicate the presence of adverse selection, but which highlighted some interesting features of the relationship between the selected variables.
本文检验了 2003 年巴西个人医疗保险市场中是否存在逆向选择。该检验方法借鉴了 Chiappori 和 Salanié（Eur Econ Rev 41, 943-950, 1997; J Polit Econ 108, 56-78, 2000）提出的方法。在控制了性别、年龄、收入、受抚养人数、职业群体和受教育程度等因素后，证据表明存在逆向选择，因为合同覆盖范围与疾病发生（如住院）之间呈正相关关系，但这种相关性并不强。在概率单位回归估计中考虑复杂抽样，得出的实证证据表明不存在逆向选择，但突出了所选变量之间关系的一些有趣特征。
