Gretchen Chapman - US grants

People are often faced with decisions involving uncertain outcomes. Rather than making judgments in accord with probability theory, past research suggests that people use a limited number of heuristics. There has been little research, however, on the process by which heuristics are selected. This proposal for a Research Planning Grant examines the question of when each heuristic is used. The principal investigator proposes that people have multiple heuristics, but that one occupies a default position. The plan is to development an experimental methodology for measuring heuristic use in probability judgment. This methodology will be used to examine factors which influence heuristic selection. The project will identify conditions which can improve the accuracy of probability estimation and enhance the quality of decisions involving uncertainty.

Time preferences indicate how much decision makers value future outcomes relative to more immediate outcomes. They can be quantified as a temporal discount rate (the increase in value necessary to offset a delay). The current research extends previous research by the PI by addressing two related research questions. First, how and why do individual discount rates differ from societal and intergenerational discount rates? Whereas most previous research has concerned time preferences that individuals display for outcomes that occur (usually to themselves) in their own lifetime, many important societal intertemporal choices involve outcomes that occur to future generations (e.g., pollution, global warming). Several theorists have argued that the discount rate applied to intergenerational choices should differ (be lower) than that applied to intragenerational decisions, but little empirical research has explored this distinction. Four experiments test two descriptive theories about how and why inter- and intra- generational discount rates might differ. The second question addressed is: can biases in intertemporal choice and choice under uncertainty be explained by common mechanisms? Although there is a sizeable body of research on intertemporal choice, most decision research continues to address choice under uncertainty. Three experiments extend previous work in drawing parallels between intertemporal choice and choice under uncertainty and test the idea that the same decision processes underlie biases in these two domains. These two research questions provide both a basic and an applied focus. These two foci are related because policy outcomes with very long delays almost invariably involve uncertainty as well as delay.

Many decisions are made on behalf of someone else. For example, family members must sometimes make medical decisions on behalf of an incapacitated loved one. The family member making the decisions (the agent) has to select the options she thinks the patient (the principal) would make if the principal could decide for himself. Economists have described this relationship in abstract terms as the principal-agent problem, where the agent is the person making decisions and the principal is the beneficiary of those decisions. In many situations, the principal has the opportunity to communicate his preferences and objectives to the agent. In surrogate health care decision making, for example, this communication often comes in the form of an advance directive for health care. Despite the recent popularity of advance directives, there is little evidence that they improve the agent's accuracy in predicting what the principal would have wanted. Such failures could result because (a) the principal may incompletely specify his preferences, and (b) the agent may have limited competence to interpret and apply the principal's objectives. The prediction made in the current research is that when such conditions apply, the agent will use one of several heuristics or short cut rules in order to make surrogate decisions on the principal's behalf. Four such heuristics are explored in the proposed studies. A question of major interest is whether use of these heuristics increases or decreases the agreement between the principal's true preferences and the surrogate decisions made by the agent.

Seven experiments are proposed. Experiments 1 and 2 will examine principal competence, agent, and when advance directives increase agreement between the agent's surrogate decisions and the decision the principal would make on his own behalf. Experiments 3 - 6 examine four heuristics or strategies hypothesized to be used by agents when they are uncertain as to the principal's preferences. In the projection heuristic, the agent uses her own preferences as a guide to the principal's preferences, sometimes resulting in surrogate decisions that are more similar to the agent's own preferences than to the principal's preferences. In the fiduciary heuristic, the agent is less willing to take risks and more willing to wait for benefits when making surrogate decisions than she would be in making decisions on his own behalf (or than the surrogate would be in making decisions on his own behalf). In the intervention heuristic, the agent role elicits a stronger preference for active or aggressive intervention-like options than does the principal role (under the assumption that principals appoint agents to "do something," rather then to do nothing). In the status quo heuristic, the agent role is associated with a strong preference to stick with the status quo. Finally, unlike Experiments 1 - 6, which will use convenience samples of lay people, Experiment 7 will use elderly medical patients and their designated family member surrogates as the principals and agents in the study.

The proposed research brings together basic research on the psychology of decision making and applied health research. It has the potential to illuminate which heuristics help and which ones hinder agents in representing the principal's preferences accurately. The findings could improve the practice of writing advance directives and promote patient autonomy by indicating how to make surrogate judgments more accurate.

When vaccination is voluntary, vaccination decisions are made by individuals. Collectively, individual decisions determine the level of population immunity, which in turn affects the utility of vaccination decisions for the individual. While children are responsible for the majority of influenza transmission, it is the elderly that suffer the most associated morbidity and mortality. Consequently, the utility of vaccine allocation to children is greater for the population than it is for the children themselves, generating a type of social dilemma. The utility to an individual of whether or not to vaccinate also depends on two principal sources of uncertainty. First, there is uncertainty inherent in the probabilistic nature of disease transmission. Second, the decisions of others introduce another level of uncertainty into the system. An individual's vaccination decision affects the likelihood of infection for others in the population. At the same time, the importance of vaccination to the individual depends on the vaccination decisions made by others. In an analogous way, a country's decision to fund disease surveillance affects the likelihood of outbreaks for other countries. In addition, the importance of surveillance to an individual country depends on the surveillance decisions of others.

We will integrate results from individual, population and global perspectives. On an individual scale, questionnaire and experimental game studies will be conducted to examine how an individual's vaccination decisions are influenced by the decisions of others, and to estimate the potential contribution of altruism to decisions. Combining individual and population scales, we will integrate a model of influenza epidemiology with a game-theoretic model of age-specific vaccine demand. Our psychological data will be used to develop our model and to verify its predictions. On a global scale, we will evaluate the relationship between the probabilities intrinsic to disease persistence, and decision making about conscientious reporting to the international community. The synthesis of these three scales of analysis with our interdisciplinary approach will illuminate the dynamics arising from the interplay between a biological disease system and human social decision processes. This interdisciplinary approach combines mathematical modeling with psychological data collection, economics with epidemiology, and individual decision making with population-level public health outcomes.

Many decisions are made in the face of risk and uncertainty and under circumstances where each person's individual decision affects other people's outcomes. The 2009 outbreak of swine flu (influenza A H1N1) provides a chance to study how lay people's perceptions of risks change over time and how those perceptions drive willingness to engage in precautionary behaviors (such as anti-viral medication use or self quarantine) that not only have consequences for the person who engages in the behaviors but that also affect the risks for others in the population. The investigators use an internet survey regarding people?s risk perception and willingness to take precautionary measures to query cohorts of US adults starting a few days after the first news of the outbreak and continuing at regular intervals throughout the epidemic. The research examines the relationships over time among information from the media about the influenza outbreak, perceptions of risk, and interest in taking precautionary measures. This outbreak of a new infectious disease represents a rare opportunity to study how risk perceptions and precautionary behaviors change over time in response to information about how the hazard unfolds. The results could have implications not only for public health responses to natural disasters but also for an understanding of the basic mechanisms underlying risk perception and decision making under uncertainty.

This dissertation research examines the decision processes underlying how people value lives saved in situations of resource scarcity. Three policies a person could use are examined: (1) treating all lives are equal, (2) prioritizing people who will gain the most benefit (e.g. additional life years) from an intervention, and (3) prioritize young people regardless of the number of years they have left to live. These metrics imply different strategies for health resource allocation, especially when such resources are scarce. Vaccination scenarios are used to probe which metrics lay people use in different situations and how the type of question influences the metric used. In direct questions, people are asked about their abstract principles (e.g., all lives are equal, prioritize the young, etc.). In indirect questions, people are given an allocation problem (e.g., there are 1000 people at risk but only 500 vaccines; who should get the vaccines?). The co-PI will test different psychological accounts for why people might express different metrics in these two types of questions.
The broader impacts of this research derive from the fact that the public's support for health policies may be malleable: While the pro-young tendencies may drive support for specific policies for how to prioritize scarce health resources (i.e. the 2009 H1N1 vaccine was prioritized for people under age 25), they depart from the oft-cited moral standard that "all lives are equal". Such tendencies may be concealed in more direct measures, such as in questions directly asking whether lives of young people are more valuable than those of older people, because answering yes in this case is a more apparent contradiction to the deep-rooted "all lives equal" moral standard. Studying these inconsistencies provides important information on how to design public health policies and how to present them to the public.

Concern for others may play a significant role in decision making. This research examines cross-national differences in the role that concern for others plays in vaccination decisions using surveys and psychological experiments. The research also examines the influence of this concern on predicted cross-national influenza vaccination rates through mathematical modeling. This interdisciplinary research integrates concepts, tools, and objectives from economics, psychology, mathematics, and epidemiology. The research involves an age-structured mathematical model of infectious-disease transmission. The model uses game theory to incorporate age-dependent vaccination decisions and statistical methods to estimate the probability that individuals will choose to vaccinate against influenza, based on responses to survey items on concern for others and perceptions of infection risk.

Focusing on the USA, Japan, France, and China, this research assesses how contact patterns and influenza vaccination decision making vary across cultures and how they can inform nation-specific strategies to promote vaccination. The interface of biological systems, indivduals' decision making, and social and cultural influences illuminates the dynamic interplay between an infectious disease and social decision making. The research is likely to discover novel ways to increase vaccination coverage against influenza, as well as other diseases, by understanding pro-social tendencies.

In this project the Principal Investigators will exam the qualitative differences between discounting functions in intertemporal choice. Mazur (1987) proposed the hyperbolic discounting function. This type of function implies frequently observed dynamic inconsistency - a preference reversal whereby the agent initially prefers the larger later reward but later changes to prefer the smaller sooner reward . Subsequent researchers have proposed alternative discounting functions to explain this and other empirical regularities. The hyperbolic discounting function is still the most widely accepted model; however, comparisons of different models have not convinced all researchers that it is the best descriptive theory. This may be because previous model comparisons have focused on quantitative differences among models, especially the curve fits between each model and data. Strictly speaking, a curve fit does not provide a decisive conclusion about whether the model is qualitatively correct or not. It only tells which function fits the data better than others. The current research aims to provide more decisive evidence by highlighting qualitative differences between models. To investigate the qualitative predictions of different models of intertemporal choice, the investigators have developed a new modeling framework that can analyze choice patterns across different delays, reward magnitudes, and individual parameters based on the specific mathematical models.

In terms of broader impacts, this research will benefit the general public and practitioners who want to promote self-regulation by providing a better understanding of the conflicts between short-term temptations and long-term benefits. It has implications in a variety of arenas, such as retirement planning, addiction treatment, healthy behavior change, and procrastination.

The question of how to facilitate pro-social behavior is one of the most pressing challenges facing behavioral scientists because answers to this question have far-reaching implications for a myriad causes of unhappiness. In many domains, such as vaccination, resource conservation, or blood donation, the outcome that is optimal for the group cannot be achieved unless individuals act beyond their narrow self-interest. The current research harnesses the principle of signaling to develop and test interventions that may inspire pro-social behavior by appealing to agents' desire to appear prosocial. Whereas some people may be motivated to contribute to the public good simply by altruistic concerns for others, even absent those purely altruistic motives, nearly everyone likes to be viewed by others as a prosocial person or to think of themselves as prosocial. In economic terms, this idea is captured by the concept of signaling -- engaging in a behavior that signals the type of person one is. Thus, a self-interested reason to engage in pro-social behavior is to signal (to oneself or to others) that one is a good person. Five sets of experiments in the current project test the idea that prosocial behavior can be increased if people are given the opportunity to use that behavior to signal their prosocial nature.

In the proposed research the investigators test the effects of interventions designed based on signaling theory for their influence on prosocial behavior in a series of field and lab experiments. First, a field study in the context of a blood drive tests whether monetary incentives motivate blood donation more effectively when framed in a way that signals the pro-social motives of the decision maker to perform the behavior. Second, a study on framing messages to emphasize the signal value of vaccination examines whether parents of young children are more likely to receive an influenza vaccination for themselves after viewing a message presenting vaccination as a signal that one puts their children first than after seeing a message presenting vaccination as a signal that one puts self-care first, or after seeing either of two control messages. Third, in a study on peer recommendation, researchers will test whether a message advocating blood donation is more effective if it emphasizes the signal value of this behavior, and whether this signaling effect is more pronounced when the message comes in the form of a personalized recommendation from a co-worker as compared to a standard message from a blood drive. Fourth, three studies on social comparison will investigate whether feedback comparing one's performance to that of others promotes performance improvement in a pro-social task because the social comparison feedback serves as a signal, indicating what the performance says about the agent. Fifth, in a series of studies using a common pool resource game, researchers will explore the effect of a partitioning manipulation that signals the equitable amount for each agent to consume into order to achieve the group optimal outcome, and they will test whether the partition serves as a coordination signal. This research extends previous work in economics, social psychology, and decision research, and it applies signaling theory to the design of interventions to facilitate pro-social behavior. The body of research combines powerful field experiments with tightly controlled laboratory experimental designs to test the efficacy of signaling interventions by assessing actual behavior and examining the decision processes underlying these effects. The findings will simultaneously shed light on the nature of both pro-social behavior and signaling mechanisms.

The purpose of the present work is to test an operationalization of norms proposed by Dr. Cristina Bicchieri, which embeds this concept into the rational actor model from decision theory. In a series of two studies, the researchers will test whether two often-cited effects in the social dilemma literature (the influence of social cues and group membership) can be accounted for by their impact on participants' beliefs about the existing social norm, as defined by Dr. Bicchieri and measured using procedures she developed. In a third study, the researchers will test the ability of Dr. Bicchieri's norm-based utility function to predict cooperation behavior across social dilemma tasks. If successful, this would support the usefulness of embedding norms into the rational choice model (as behavioral economists have been doing with other "social preferences"). Lastly, a fourth study will test Dr. Bicchieri's claim that the norms that solve coordination problems (where self and social interests dovetail) are sustained via a different mechanism than those that solve social dilemmas (where self and social interests diverge). In particular, we will observe whether third-party reward, punishment, and compensation behavior differs as a function of the type of norm necessary to reach the socially optimal outcome. Evidence in line with our predictions would support Dr. Bicchieri?s dichotomy of norms into two types and present another method for detecting the existence of norms other than belief elicitation.

The norms of an environment influence people's expectations about what is commonly done and what is commonly approved or disapproved. These expectations can subsequently influence a person's actions as norm-abiding behavior is informally rewarded and violations are punished (starting with gossip, ostracism, and then exclusion). From a policy perspective, efforts aimed at improving the welfare of society by introducing formal rules will benefit from an examination of the current informal rules governing a group's actions. To the extent that the existing informal rules legitimize the formal ones, the cost of enforcing the new formal rules will be lower and vice versa. However, the concept of norms remains imprecise, and real-world applications remain infeasible, without an operational definition and a model of their impact on behavior.

Obesity rates continue to rise, despite increased funding for nutrition education and policies to encourage healthy choices. This project addresses the question of how to get consumers to make healthier food choices without asking them to work hard to do so. Finding answers to this question may be the key to reducing the obesity epidemic. The proposed research harnesses concepts from behavioral economics to make the healthy option the salient and easy choice. The filed experiments in this project offer an opportunity to study customers making decisions with real dietary consequences. The studies focus on consumption of French fries, soda, and desserts. The results can be extrapolated to other foods and applied to encouraging or discouraging a variety of dietary choices. From an economic standpoint, in addition to promoting health, the interventions could allow for-profit establishments to make more money by offering a smaller portion of a food item but still garner customer satisfaction.

The objective of this project is to examine the role psychological processes (affective versus cognitive) play in making food choices. Using novel methodologies that include acquiring individual level data on customer transactions, the research will investigate interventions to nudge people toward making healthy food choices. The project entails two field studies, both to be conducted within the foodservice operation of a large public university. The two studies focus on manipulations to decrease portion sizes of indulgent foods by appealing to emotional (affective processing) or non-emotional (cognitive) motives. The aim of the first study is to compare a charity/pro-social motive (tapping a hypothesized emotional mechanism) to a nutrition/self-interest motive (tapping a hypothesized cognitive mechanism) in their effectiveness in nudging college students to downsize their French fry portion and/or accept fountain water instead of soda. The aim of the second study is to examine whether manipulating menu descriptions can impact satisfaction with food consumed. The researchers predict that a sensory-rich, detailed (emotional) description of a dessert can, in effect, substitute for size of the dessert, making diners just as satisfied with a small portion of dessert as they would with a larger portion of the same dessert, absent the decadent, emotionally-detailed description. Both studies will test the "emotion effect" in getting individuals to eat less while feeling virtuous and satisfied with smaller portions.

The coronavirus outbreak poses a major challenge for our health system. As people become sick and need medical care, they need resources like hospital beds and ventilators. However, if many people become sick in a short period of time, there will not be enough of these resources to care for them all. If we are to treat every sick person with the best possible medical care, we need to both prevent and delay new infections. We know from history and medical science that public behavior is the most important tool for this prevention. But for the public to help, people need to know what to do and how to do it, as well as to understand why these behaviors are so important. People take their cues from those around them in making sense of new, uncertain situations. This makes it important to make sure that everybody is getting good information about the risks of Covid-19 and how to prevent it. Official messages need to reflect scientific knowledge, and myths that pop up in communities need to be addressed so that people can understand and debunk them. The research team has been studying how people are thinking about the risks of Covid-19, and what they are doing to protect themselves and their community. One key finding from that work is that when people are uncertain about the risk, they are more likely to rely on what other people are doing to determine what the right thing to do is. The team also finds that people's main concerns about social distancing are that they are worried about getting by without a paycheck and how they will get food and meet other urgent needs. This project involves surveys and experiments to better understand these concerns and provide new knowledge to help guide policy action. First, we need to know whether helping people understand how to prevent infection will actually lead them to protect themselves. The experiments test and identify how best to help people understand, especially for those who are not fully engaging in social distancing. Then, over the next few months as the situation changes, the research team develops messages to help people understand what is happening and how their behavior can help protect themselves and the people around them.

In early March 2020, the researchers conducted an exploratory survey to determine whether some protective behaviors were reported at low levels and identify predictors of poor compliance. The research showed that compliance with the more extreme social distancing behaviors appear to be dependent on social norms, with rates being lower when other people do not seem to be engaging in such distancing. Furthermore, people appear to rely on those norms particularly when they experience more uncertainty about the risk. The findings also were that concerns about losing pay and disruption of personal plans are most predictive of anticipated failures to comply with orders to stay home, followed by the need to shop for food and other urgent needs. These findings suggest that a policy approach aimed at getting people through financial and logistical hardship is critically important and has the potential to be highly impactful. The new research explores more deeply these concerns and how they relate to protective actions. The first phase establishes which predictive factors have causal influence on protective behaviors. The second phase is an assessment of how well protective behaviors are being performed and identifies causally predictive factors identified in the first phase for a nationally representative sample (oversampling high-risk geographical locations). In the third phase, iteratively for each causal factor, the team develops and pilots messages in a test-bed environment, testing final messages with an experimental design in a national sample (repeating regularly as the environment and pandemic evolve), and following up on a subset of critical messages with a 3-day retest to assess behavior change. Finally, again iteratively for each effective message, the team disseminates recommended messages along with the rationale for why they are useful and how they are understood to work. The team shares its findings with its established network of public health officials.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.