Thomas Graeber

Photo Thomas Graeber

Current position: Post-Doctoral Fellow at Harvard University, Dept. of Economics
Primary fields: Behavioral Economics, Experimental Economics

I will join Harvard Business School as an Assistant Professor in July 2020.

Please find my [CV here]. Contact me at [].

Benjamin Enke and I are currently looking to hire a pre-doctoral fellow at Harvard. Please see the job posting [here] and apply [here].


Cognitive Uncertainty
with Benjamin Enke
[abstract]   [pdf]   [media coverage: The Economist]
This paper introduces a formal definition and an experimental measurement of the concept of cognitive uncertainty: people’s subjective uncertainty about what the optimal action is. This concept allows us to bring together and partially explain a set of behavioral anomalies identified across four distinct domains of decision-making: choice under risk, choice under ambiguity, belief updating, and survey expectations about economic variables. In each of these domains, behavior in experiments and surveys tends to be insensitive to variation in probabilities, as in the classical probability weighting function. Building on existing models of noisy Bayesian cognition, we formally propose that cognitive uncertainty generates these patterns by inducing people to compress probabilities towards a mental default of 50:50. We document experimentally that the responses of individuals with higher cognitive uncertainty indeed exhibit stronger compression of probabilities in choice under risk and ambiguity, belief updating, and survey expectations. Our framework makes predictions that we test using exogenous manipulations of both cognitive uncertainty and the location of the mental default. The results provide causal evidence for the role of cognitive uncertainty in belief formation and choice, which we quantify through structural estimations.

Inattentive Inference
[abstract]   [pdf]
This paper studies why belief formation errors arise in a novel updating task that captures a key feature of information structures in practice: people need to learn about a state of the world from information that also depends on other unobserved states. For example, consider someone trying to infer effort (X) from observed performance (S = X + Y), which is also influenced by luck (Y). The first part of the paper uses a series of laboratory and online experiments to causally demonstrate a pervasive neglect of alternative causes in information structures, leading to excessively sensitive and overprecise beliefs. The second part explores the mechanisms behind this neglect. Evidence from more than twenty treatments consistently shows that inattention to alternative causes is not driven by excessive complexity, computational errors or deliberate effort reduction. Instead, people spontaneously form incomplete mental models of the problem that determine how information is processed. They are confident in their misspecified models and unaware of the resulting error. These mental representations are not stable but context-dependent: cues that direct attention to the neglected part of the problem alleviate the bias.

Heterogeneity of Gain-Loss Attitudes and Expectations-Based Reference Points
with Lorenz Goette, Alex Kellogg and Charles Sprenger
[abstract]   [pdf]
This project examines the role of heterogeneity in gain-loss attitudes for identifying models of expectations-based reference dependence (Kőszegi and Rabin, 2006, 2007) (KR). Different gain-loss attitudes lead to different signs for KR comparative statics. Failure to account for the known heterogeneity in gain-loss attitudes is a central confounding factor challenging prior tests of the KR model conducted under the assumption of universal loss aversion. We document heterogeneous treatment effects over gain-loss types in both an initial experiment and an exact replication. Recognizing heterogeneity over types allows us to both recover the KR model’s central predictions, and account for inconsistency across prior empirical tests.

Delayed Negative Effects of Prosocial Spending on Happiness
with Armin Falk   (Forthcoming at Proceedings of the National Academy of Sciences)
Does prosocial behavior promote happiness? We test this longstanding hypothesis in a behavioral experiment that extends the scope of previous studies. In our Saving a Life paradigm, every participant either saved one human life by triggering a targeted donation of 350 euros, or received an amount of 100 euros. Using a choice paradigm between two binary lotteries with different chances of saving a life, we observed subjects’ intentions at the same time as creating random variation in prosocial outcomes. We repeatedly measured happiness at various delays. Our data replicates the positive effect identified in previous research, but only for the very short run. One month later, the sign of the effect reversed, and prosocial behavior led to significantly lower happiness than obtaining the money. Our findings revealed a more nuanced causal relationship than previously suggested, providing an explanation for the apparent absence of universal prosocial behavior.