The Increasingly Mixed Proportional Hazard Model: An Application to Socioeconomic Status, Health Shocks, and Mortality
提出一种新的持续时间模型（IMPH），用于处理未观测到的累积个体特定冲击，并应用于德国社会经济面板数据，发现该模型比传统MPH模型拟合更好，且未观测健康冲击和社会经济地位对预测寿命有重要作用。
We introduce a duration model that allows for unobserved cumulative individual-specific shocks, which are likely to be important in explaining variations in duration outcomes, such as length of life and time spent unemployed. The model is also a useful tool in situations where researchers observe a great deal of information about individuals when first interviewed in surveys but little thereafter. We call this model the “increasingly mixed proportional hazard” (IMPH) model. We compare and contrast this model with the mixed proportional hazard (MPH) model, which continues to be the workhorse of applied single-spell duration analysis in economics and the other social sciences. We apply the IMPH model to study the relationships among socioeconomic status, health shocks, and mortality, using 19 waves of data drawn from the German Socio-Economic Panel (SOEP). The IMPH model is found to fit the data statistically better than the MPH model, and unobserved health shocks and socioeconomic status are shown to play powerful roles in predicting longevity.