Negative and zero time preference for health
研究发现多数人对健康有正时间偏好，但相当一部分人表现出负或零时间偏好，且性别、教育、健康状态感知等因素影响偏好方向。
The assumption of positive time preference is seldom challenged in analyses of intertemporal choices, despite considerable evidence of zero and negative discount rates. In this study, the majority of respondents have positive discount rates, but a substantial number have negative or zero discount rates. Using probit regression, the perception of the severity of the health-state, gender, education and perception of the questions in terms of difficulty are shown to influence whether individuals have positive discount rates. Copyright © 2000 John Wiley & Sons, Ltd.