Ido Erev
Biographic Data
| ID | 77751 |
|---|---|
| NAME | Ido Erev |
| GIVEN NAMES | Ido |
| FAMILY NAME | Erev |
| SIGNATURE | EREV I |
| AFFILIATIONS | Technion – Israel Institute of Technology |
| ORCID | 0000-0001-9889-4070 |
| VERIFIED | Yes |
| TOTAL WORKS | 36 |
| TOTAL CITATIONS | 214 |
| AUTHOR COUNT | 36 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1989 |
| LATEST PUBLICATION YEAR | 2026 |
| H-INDEX | 8 |
Warning: Warnings Can Backfire Even When They Provide New and Important Information
We clarify the conditions under which warnings that provide useful information backfire. Our analysis is based on three observations: (1) warnings can increase the attention given to the warned‐against behavior, (2) in many settings, counterproductive warned‐against behaviors (like texting while driving) are typically rewarding, and (3) decisions from experience reflect insufficient sensitivity to rare outcomes. A simple model that abstracts the …
Predicting human decisions with behavioural theories and machine learning
The Relative Importance of the Contrast and Assimilation Effects in Decisions Under Risk
Past research on decisions under risk has documented two contradictory context effects: the contrast effect, where risk preferences in “target” tasks diverge from those in previous “surrounding” tasks, and the assimilation effect that implies the opposite bias. We present four web experiments (three preregistered) that clarify the conditions determining the relative prominence of these opposing effects. Our experiments focus on choice patterns in…
Sampling in Judgment and Decision Making
Sampling approaches to judgment and decision making are distinct from traditional accounts in psychology and neuroscience. While these traditional accounts focus on limitations of the human mind as a major source of bounded rationality, the sampling approach originates in a broader cognitive-ecological perspective. It starts from the fundamental assumption that in order to understand intra-psychic cognitive processes one first has to understand t…
The common origin of both oversimplified and overly complex decision rules
Many deviations from rational choice imply the neglect of important evidence and suggest the use of simple heuristics. In contrast, other deviations imply sensitivity to irrelevant evidence and suggest the use of overly complex rules. The current analysis takes two steps toward identifying the conditions that trigger these contradictory deviations from efficient reasoning. The first step involves a theoretical analysis. It shows that the contradi…
Conformity and Group Performance
This research provides evidence regarding the causal effect of group conformity on task performance in stable and variable environments. Drawing on studies in cultural evolution, social learning, and social psychology, we experimentally tested the hypotheses that conformity improves group performance in a stable environment (H1) and decreases performance (by hindering adaptability) in a temporally variable environment (H2). We compare the perform…
The impact of experience on decisions based on pre-choice samples and the face-or-cue hypothesis
Promoting healthy behavior through repeated deposit contracts: An intervention study
Complacency, panic, and the value of gentle rule enforcement in addressing pandemics
The impact of rewarding medium effort and the role of sample size
We take the point‐of‐view of designers of incentive systems who cannot reward the behavior they most desire, and must decide whether to reward a less desired behavior. For example, when it is difficult to distinguish between the desired high‐effort strategy from a low‐effort “mimicry” strategy, policy makers may choose instead to reward medium levels of effort. Experiments 1 and 2 examine situations in which participants (the subjects of the poli…
The impact of variability and prechoice experience on taking safety measures: The case of security updates
The goal of this research is to clarify the conditions that trigger reluctance to take cost‐effective safety measures. We present three experiments. In two of the experiments, the participants were asked to operate a simulated system for 20 periods, each with 10 trials. They could “update the system” to eliminate the risk of a “security failure” that led to a loss of 100 points. The updating cost was either fixed (at 10 points) or variable (initi…
The Reinforcing Value of Lottery Tickets, and the Synergetic Effect of Distinct Reinforcements
We present two experiments that explore the reinforcing value of lottery tickets. Participants are faced with a repeated choice task between a safe alternative and a risky prospect that provides a chance to win a lottery ticket to be played at the end of the study. Study 1 considers situations in which the risky option leads to a slightly higher expected value than the safe alternative. It shows that the risk‐taking rate increases with the probab…
Click or Skip: The Role of Experience in Easy-Click Checking Decisions
New websites and smartphone applications provide easy-click checking opportunities that can help consumers in many domains. However, this technology is not always used effectively. For example, many consumers skip checking Terms and Conditions links even when a quick evaluation of the terms can save them money, but they check their smartphone while driving even though this behavior is illegal and dangerous. Four laboratory experiments clarify the…
Cross cultural differences in decisions from experience: Evidence from Denmark, Israel, and Taiwan
On the Decision to Explore New Alternatives: The Coexistence of Under‐ and Over‐exploration
The decision whether to explore new alternatives or to choose from familiar ones is implicit in many of our daily activities. How is this decision made? When will deviation from optimal exploration be observed? The current paper examines exploration decisions in the context of a multi‐alternative “decisions from experience” task. In each trial, participants could choose a familiar option (the status quo) or a new alternative (risky exploration). …
Adaptive behavior leads to under-diversification
The description–experience gap in risky choice
A choice prediction competition: Choices from experience and from description
Erev, Ert, and Roth organized three choice prediction competitions focused on three related choice tasks: One shot decisions from description (decisions under risk), one shot decisions from experience, and repeated decisions from experience. Each competition was based on two experimental datasets: An estimation dataset, and a competition dataset. The studies that generated the two datasets used the same methods and subject pool, and examined deci…
The combined effect of information and experience on drivers’ route-choice behavior
Loss aversion, diminishing sensitivity, and the effect of experience on repeated decisions
Three experiments are presented that explore the assertion that loss aversion and diminishing sensitivity drive the effect of experience on choice behavior. The experiments are focused on repeated choice tasks where decision makers choose repeatedly between alternatives and get feedback after each choice. Experiments 1a and 1b show that behavioral tendencies that were previously interpreted as indications of loss aversion in decisions from experi…
The rejection of attractive gambles, loss aversion, and the lemon avoidance heuristic
Replicated alternatives and the role of confusion, chasing, and regret in decisions from experience
The current paper explores choice among alternatives that can be classified into distinct classes. All the members of a particular class were ‘replicated alternatives’: they promised the same payoff distribution. Information to decision makers was limited to feedback concerning the realized (obtained and foregone) payoffs. Experiment 1 demonstrates that increasing the number of replicated alternatives creates confusion (which facilitates random c…
The Role of Personal Experience in Contributing to Different Patterns of Response to Rare Terrorist Attacks
An examination of the behavioral effect of repeated terrorist attacks reveals that local residents (of the attacked area) appear to be much less sensitive to this risk than international tourists. Furthermore, the limited sensitivity on the part of local residents seems to diminish with time, even when the attacks continue. An experimental study shows a similar pattern in a laboratory experiment that focuses on a basic decision task: when making …
Decisions from Experience and the Effect of Rare Events in Risky Choice
When people have access to information sources such as newspaper weather forecasts, drug-package inserts, and mutual-fund brochures, all of which provide convenient descriptions of risky prospects, they can make decisions from description. When people must decide whether to back up their computer's hard drive, cross a busy street, or go out on a date, however, they typically do not have any summary description of the possible outcomes or their li…
Small feedback‐based decisions and their limited correspondence to description‐based decisions
The present paper explores situations in which the information available to decision makers is limited to feedback concerning the outcomes of their previous decisions. The results reveal that experience in these situations can lead to deviations from maximization in the opposite direction of the deviations observed when the decisions are made based on a description of the choice problem. Experience was found to lead to a reversed common ratio/cer…
Constructive Intergroup Competition as a Solution to the Free Rider Problem: A Field Experiment
The Role of Personal Experience in Contributing to Different Patterns of Response to Rare Terrorist Attacks
An examination of the behavioral effect of repeated terrorist attacks reveals that local residents (of the attacked area) appear to be much less sensitive to this risk than international tourists. Furthermore, the limited sensitivity on the part of local residents seems to diminish with time, even when the attacks continue. An experimental study shows a similar pattern in a laboratory experiment that focuses on a basic decision task: when making …
Small feedback‐based decisions and their limited correspondence to description‐based decisions
The present paper explores situations in which the information available to decision makers is limited to feedback concerning the outcomes of their previous decisions. The results reveal that experience in these situations can lead to deviations from maximization in the opposite direction of the deviations observed when the decisions are made based on a description of the choice problem. Experience was found to lead to a reversed common ratio/cer…
Provision of Step-Level Public Goods: The Sequential Contribution Mechanism
Groups of five players participated in a social dilemma game in which each player receives a monetary endowment and then chooses whether to contribute it to a monetary public good. The good is provided to all group members if at least three contributions are made; it is not provided, otherwise. Experiment 1 showed that the simultaneous protocol of play—where decisions are made privately and anonymously—is significantly less effective in solving t…
A choice prediction competition: Choices from experience and from description
Erev, Ert, and Roth organized three choice prediction competitions focused on three related choice tasks: One shot decisions from description (decisions under risk), one shot decisions from experience, and repeated decisions from experience. Each competition was based on two experimental datasets: An estimation dataset, and a competition dataset. The studies that generated the two datasets used the same methods and subject pool, and examined deci…
Loss aversion, diminishing sensitivity, and the effect of experience on repeated decisions
Three experiments are presented that explore the assertion that loss aversion and diminishing sensitivity drive the effect of experience on choice behavior. The experiments are focused on repeated choice tasks where decision makers choose repeatedly between alternatives and get feedback after each choice. Experiments 1a and 1b show that behavioral tendencies that were previously interpreted as indications of loss aversion in decisions from experi…
Intergroup competition for public goods: Effects of unequal resources and relative group size
The Effect of Repeated Play in the IPG and IPD Team Games
Repeated interaction in integroup conflict was studied in the context of two team games: the intergroup public goods (IPG) game and the intergroup prisoner's dilemma (IPD) game. The results reveal (a) a main effect for game type; subjects were twice as likely to contribute toward their group effort in the IPG game than in the IPD game, and (b) a Game-Type × Time interaction; subjects contributed less over time in the IPD game while continuing to …
On the Decision to Explore New Alternatives: The Coexistence of Under‐ and Over‐exploration
The decision whether to explore new alternatives or to choose from familiar ones is implicit in many of our daily activities. How is this decision made? When will deviation from optimal exploration be observed? The current paper examines exploration decisions in the context of a multi‐alternative “decisions from experience” task. In each trial, participants could choose a familiar option (the status quo) or a new alternative (risky exploration). …
The rejection of attractive gambles, loss aversion, and the lemon avoidance heuristic
Cross cultural differences in decisions from experience: Evidence from Denmark, Israel, and Taiwan
The common origin of both oversimplified and overly complex decision rules
Many deviations from rational choice imply the neglect of important evidence and suggest the use of simple heuristics. In contrast, other deviations imply sensitivity to irrelevant evidence and suggest the use of overly complex rules. The current analysis takes two steps toward identifying the conditions that trigger these contradictory deviations from efficient reasoning. The first step involves a theoretical analysis. It shows that the contradi…
Complacency, panic, and the value of gentle rule enforcement in addressing pandemics
The Reinforcing Value of Lottery Tickets, and the Synergetic Effect of Distinct Reinforcements
We present two experiments that explore the reinforcing value of lottery tickets. Participants are faced with a repeated choice task between a safe alternative and a risky prospect that provides a chance to win a lottery ticket to be played at the end of the study. Study 1 considers situations in which the risky option leads to a slightly higher expected value than the safe alternative. It shows that the risk‐taking rate increases with the probab…
Replicated alternatives and the role of confusion, chasing, and regret in decisions from experience
The current paper explores choice among alternatives that can be classified into distinct classes. All the members of a particular class were ‘replicated alternatives’: they promised the same payoff distribution. Information to decision makers was limited to feedback concerning the realized (obtained and foregone) payoffs. Experiment 1 demonstrates that increasing the number of replicated alternatives creates confusion (which facilitates random c…
The Relative Importance of the Contrast and Assimilation Effects in Decisions Under Risk
Past research on decisions under risk has documented two contradictory context effects: the contrast effect, where risk preferences in “target” tasks diverge from those in previous “surrounding” tasks, and the assimilation effect that implies the opposite bias. We present four web experiments (three preregistered) that clarify the conditions determining the relative prominence of these opposing effects. Our experiments focus on choice patterns in…
The impact of rewarding medium effort and the role of sample size
We take the point‐of‐view of designers of incentive systems who cannot reward the behavior they most desire, and must decide whether to reward a less desired behavior. For example, when it is difficult to distinguish between the desired high‐effort strategy from a low‐effort “mimicry” strategy, policy makers may choose instead to reward medium levels of effort. Experiments 1 and 2 examine situations in which participants (the subjects of the poli…
The impact of variability and prechoice experience on taking safety measures: The case of security updates
The goal of this research is to clarify the conditions that trigger reluctance to take cost‐effective safety measures. We present three experiments. In two of the experiments, the participants were asked to operate a simulated system for 20 periods, each with 10 trials. They could “update the system” to eliminate the risk of a “security failure” that led to a loss of 100 points. The updating cost was either fixed (at 10 points) or variable (initi…
Adaptive behavior leads to under-diversification
The effect of explicit probabilities on decision weights and on the reflection effect
An experiment is presented that explores the finding that a request to judge probabilities can bias subsequent decisions (Erev et al. , 1993). Subjects chose among gambles whose outcomes were determined by the occurrence of events in a video game environment. The probabilities of the events could be assessed based on the visual display. In the no‐probabilities condition the subjects simply indicated their choices. In the subjective‐probability co…
Intergroup competition for public goods: Effects of unequal resources and relative group size
Provision of Step-Level Public Goods: The Sequential Contribution Mechanism
Groups of five players participated in a social dilemma game in which each player receives a monetary endowment and then chooses whether to contribute it to a monetary public good. The good is provided to all group members if at least three contributions are made; it is not provided, otherwise. Experiment 1 showed that the simultaneous protocol of play—where decisions are made privately and anonymously—is significantly less effective in solving t…
The effect of explicit probabilities on decision weights and on the reflection effect
An experiment is presented that explores the finding that a request to judge probabilities can bias subsequent decisions (Erev et al. , 1993). Subjects chose among gambles whose outcomes were determined by the occurrence of events in a video game environment. The probabilities of the events could be assessed based on the visual display. In the no‐probabilities condition the subjects simply indicated their choices. In the subjective‐probability co…
Constructive Intergroup Competition as a Solution to the Free Rider Problem: A Field Experiment
Simultaneous over- and underconfidence: The role of error in judgment processes.
The Effect of Repeated Play in the IPG and IPD Team Games
Repeated interaction in integroup conflict was studied in the context of two team games: the intergroup public goods (IPG) game and the intergroup prisoner's dilemma (IPD) game. The results reveal (a) a main effect for game type; subjects were twice as likely to contribute toward their group effort in the IPG game than in the IPD game, and (b) a Game-Type × Time interaction; subjects contributed less over time in the IPD game while continuing to …
Learning in extensive-form games: Experimental data and simple dynamic models in the intermediate term
Introduction to this Special Issue on Stochastic and Cognitive Models of Confidence
On the Importance of Random Error in the Study of Probability Judgment. Part I: New Theoretical Developments
Erev, Wallsten, and Budescu (1994) demonstrated that over- and underconfidence can be observed simultaneously in judgment studies, as a function of the method used to analyze the data. They proposed a general model to account for this apparent paradox, which assumes that overt responses represent true judgments perturbed by random error. To illustrate that the model reproduces the pattern of results, they assumed perfectly calibrated true opinion…
Evaluating and Combining Subjective Probability Estimates
This paper concerns the evaluation and combination of subjective probability estimates for categorical events. We argue that the appropriate criterion for evaluating individual and combined estimates depends on the type of uncertainty the decision maker seeks to represent, which in turn depends on his or her model of the event space. Decision makers require accurate estimates in the presence of aleatory uncertainty about exchangeable events, diag…
Introduction to this Special Issue on Stochastic and Cognitive Models of Confidence
Small feedback‐based decisions and their limited correspondence to description‐based decisions
The present paper explores situations in which the information available to decision makers is limited to feedback concerning the outcomes of their previous decisions. The results reveal that experience in these situations can lead to deviations from maximization in the opposite direction of the deviations observed when the decisions are made based on a description of the choice problem. Experience was found to lead to a reversed common ratio/cer…
Decisions from Experience and the Effect of Rare Events in Risky Choice
When people have access to information sources such as newspaper weather forecasts, drug-package inserts, and mutual-fund brochures, all of which provide convenient descriptions of risky prospects, they can make decisions from description. When people must decide whether to back up their computer's hard drive, cross a busy street, or go out on a date, however, they typically do not have any summary description of the possible outcomes or their li…
The Role of Personal Experience in Contributing to Different Patterns of Response to Rare Terrorist Attacks
An examination of the behavioral effect of repeated terrorist attacks reveals that local residents (of the attacked area) appear to be much less sensitive to this risk than international tourists. Furthermore, the limited sensitivity on the part of local residents seems to diminish with time, even when the attacks continue. An experimental study shows a similar pattern in a laboratory experiment that focuses on a basic decision task: when making …
Replicated alternatives and the role of confusion, chasing, and regret in decisions from experience
The current paper explores choice among alternatives that can be classified into distinct classes. All the members of a particular class were ‘replicated alternatives’: they promised the same payoff distribution. Information to decision makers was limited to feedback concerning the realized (obtained and foregone) payoffs. Experiment 1 demonstrates that increasing the number of replicated alternatives creates confusion (which facilitates random c…
The combined effect of information and experience on drivers’ route-choice behavior
Loss aversion, diminishing sensitivity, and the effect of experience on repeated decisions
Three experiments are presented that explore the assertion that loss aversion and diminishing sensitivity drive the effect of experience on choice behavior. The experiments are focused on repeated choice tasks where decision makers choose repeatedly between alternatives and get feedback after each choice. Experiments 1a and 1b show that behavioral tendencies that were previously interpreted as indications of loss aversion in decisions from experi…
The rejection of attractive gambles, loss aversion, and the lemon avoidance heuristic
The description–experience gap in risky choice
A choice prediction competition: Choices from experience and from description
Erev, Ert, and Roth organized three choice prediction competitions focused on three related choice tasks: One shot decisions from description (decisions under risk), one shot decisions from experience, and repeated decisions from experience. Each competition was based on two experimental datasets: An estimation dataset, and a competition dataset. The studies that generated the two datasets used the same methods and subject pool, and examined deci…
Adaptive behavior leads to under-diversification
On the Decision to Explore New Alternatives: The Coexistence of Under‐ and Over‐exploration
The decision whether to explore new alternatives or to choose from familiar ones is implicit in many of our daily activities. How is this decision made? When will deviation from optimal exploration be observed? The current paper examines exploration decisions in the context of a multi‐alternative “decisions from experience” task. In each trial, participants could choose a familiar option (the status quo) or a new alternative (risky exploration). …
Cross cultural differences in decisions from experience: Evidence from Denmark, Israel, and Taiwan
The Reinforcing Value of Lottery Tickets, and the Synergetic Effect of Distinct Reinforcements
We present two experiments that explore the reinforcing value of lottery tickets. Participants are faced with a repeated choice task between a safe alternative and a risky prospect that provides a chance to win a lottery ticket to be played at the end of the study. Study 1 considers situations in which the risky option leads to a slightly higher expected value than the safe alternative. It shows that the risk‐taking rate increases with the probab…
Click or Skip: The Role of Experience in Easy-Click Checking Decisions
New websites and smartphone applications provide easy-click checking opportunities that can help consumers in many domains. However, this technology is not always used effectively. For example, many consumers skip checking Terms and Conditions links even when a quick evaluation of the terms can save them money, but they check their smartphone while driving even though this behavior is illegal and dangerous. Four laboratory experiments clarify the…
Psychology (28 works) · Decision-Making and Behavioral Economics (25 works) · Computer Science (24 works) · Economics (19 works) · Social Psychology (15 works) · Mathematics (14 works) · Microeconomics (13 works) · Experimental Behavioral Economics Studies (12 works) · Social Psychology (12 works) · Cognitive psychology (10 works)