Poverty, Stress, and Discounting: A potential micro-mechanism for behavior change

项目摘要 受注意力缺陷多动障碍、强迫性赌博行为、尼古丁等多种疾病影响的人 成瘾和酗酒有一个共同的特点：异常高的冲动。特别是，他们倾向于立即 延迟奖励这种主观价值随时间的减少被称为时间折扣。陡颞 折扣已被证明与负面结果有关，减少折扣的干预措施 表现出积极的福利效应。 然而，令人惊讶的是，很少有证据表明时间偏好是如何产生的，以及环境因素是如何塑造的。 他们这个提议检验了一个简单的假设，即短视的时间偏好是如何内生产生的。 具体来说，我们假设贫困导致压力，压力导致短视的时间偏好， 短视偏好反过来又加剧了贫困。因此，我们的建议旨在确定一个潜在的微观机制， 行为改变为了建立这种机制的通用性，我们将在两个开发中进行实验， 和发达国家，无论是在实验室和在外地;我们的目标是建立因果关系，在所有的研究，并采用 新的福利措施（皮质醇和细胞因子）。 首先，在一个实验室实验中，我们问压力是否对时间折扣有因果影响; 参与者，并随后衡量其对时间贴现的影响。这个实验将揭示压力是否会导致 短视的决策。 在第二项研究中，我们问贫穷是否会造成压力和短视的选择。我们开发了一个新的实验室 模仿贫困的一些特征，然后问a）这种操纵是否会增加压力水平 标记皮质醇和α-淀粉酶，和B）是否“较穷”的人比其他人表现出更高的时间折扣。这 研究结果表明，贫穷可能会造成压力和短视的选择。 第三项研究是在实地进行的，在一个发展中国家进行，并要求了解贫困增加对发展中国家的因果影响。 行为我们利用肯尼亚南部马赛人独特的自然实验：使用降雨数据作为 工具变量，我们可以确定贫困的外生增加对压力和时间的因果影响， 贴现 最后，第四项研究测试了匡威的问题，即贫困减少的外生影响 并导致更有远见的决策。这项研究将包括在肯尼亚进行的一项随机对照试验， 随机选择的贫困家庭接受无条件的现金转移，免费医疗保险，或没有干预。 通过这些外生干预，我们可以识别扶贫对行为的因果效应。所有这些 研究将回答上述短视决策的候选机制是否经得起因果关系的考验 审查，从而确定一个潜在的微观机制的行为变化。(29行）

Project Summary Persons affected by conditions as diverse as Attention Deficit Hyperactivity Disorder, compulsive gambling behavior, nicotine addiction, and alcoholism share a common trait: abnormally high impulsivity. In particular, they tend to prefer immediate to delayed rewards. This decrease of subjective value over time is referred to as temporal discounting. Steep temporal discounting has been shown to be associated with negative outcomes, and interventions that reduce discounting have shown positive welfare effects. Surprisingly, however, very little evidence exists of how temporal preferences arise and which environmental forces shape them. This proposal tests a simple hypothesis of how short-sighted temporal preferences could arise endogenously. Specifically, we hypothesize that poverty leads to stress, stress leads to short-sighted temporal preferences, and short-sighted preferences in turn reinforce poverty. Thus, our proposal seeks to identify a potential micro-mechanism for behavioral change. To establish the generality of this mechanism, we will conduct experiments in both developing and developed countries, both in the laboratory and in the field; we aim to establish causality in all studies, and employ novel measures of welfare (cortisol and cytokines). First, in a laboratory experiment, we ask whether stress has a causal effect on temporal discounting; we induce stress in participants and subsequently measure its effect on temporal discounting. This experiment will reveal whether stress leads to short-sighted decision-making. In the second study, we ask whether poverty causes stress and short-sighted choices. We develop a novel laboratory paradigm that mimics some features of poverty, and then ask a) whether this manipulation increases levels of the stress markers cortisol and alpha-amylase, and b) whether "poorer" people show higher temporal discounting than others. This result would suggest that poverty may cause stress and short-sighted choices. The third study takes place in the field, and in a developing country, and asks for the causal effect of a poverty increase on behavior. We take advantage of a unique natural experiment among the Maasai of Southern Kenya: using rainfall data as an instrumental variable, we can identify the causal effect of an exogenous increase in poverty on stress and temporal discounting. Finally, the fourth study tests the converse question, namely the effects of an exogenous decrease in poverty decreases stress and leads to more far-sighted decision-making. This study will consist of a randomized controlled trial in Kenya, in which randomly selected poor households receive an unconditional cash transfer, free health insurance, or no intervention. Through these exogenous interventions, we can identify the causal effect of poverty alleviation on behavior. Together, these studies will answer whether the candidate mechanism for short-sighted decision-making outlined above withstands causal scrutiny, and thus identify a potential micro-level mechanism for behavioral change. (29 lines)