Research

BrainCake

I am a neuroeconomist and experimental economist and study how individuals make decisions. I am particularly fascinated by people sometimes making seemingly irrational decisions. I believe that many of these irrationalities can be rationally explained as a direct consequence of the limitations placed on our nervous system. I hope to understand how to minimise such irrationalities with smart choice architecture. My ultimate goal is to relate insights from my research to applied work, especially in the area of policy interventions, optimal organizational and incentives design, finance, political economics, and marketing.

In press

15. Tymula A. and Glimcher P.W. (in press). Emotions through the lens of economic theory. In Fox, A. S., Lapate, R. C., Shackman, A. J. & Davidson, R. J. (Eds.), The Nature of Emotion. Fundamental questions (2nd Edition). New York: Oxford University Press [full text]

Published papers

14. Glimcher, P.W. and Tymula, A. (2017) Let the sunshine in? The effects of luminance on economic preferences, choice consistency and dominance violations. PLoS ONE, 12(8): e0181112, August 2017 [full text]

13. Tymula A. (2017) Tolerance for ambiguity. In Moghaddam F.M. (Ed.) The SAGE Encyclopaedia of Political Behavior, SAGE Publications, Thousand Oaks CA [full text]

12. Tymula, A. (2017) Competitive Screening of Heterogenous Labor Force and Corporate Teamwork Attitude. Journal of Institutional and Theoretical Economics, 173(3), 523-547, September 2017 [full text]

11. Grubb M., Tymula A., Gilaie-Dotan S., Glimcher P. and Ifat Levy (2016) Neuroanatomy accounts for age-related changes in risk preferences. Nature Communications, 7, December 2016 [full text]

10. Tymula, A., Plassmann, H. (2016) Context-dependency in valuation. Current Opinion in Neurobiology, Volume 40, October 2016, p. 59-65 [full text]

9. Tymula, A., Woelbert, E., Glimcher, P.W. (2016) Flexible Valuations for Consumer Goods as Measured by the Becker-DeGroot-Marschak Mechanism. Journal of Neuroscience, Psychology, and Economics, Volume 9(2), June 2016, p.65-77. [full text]

8.   Tymula, A. and Glimcher, P.W. (2015) Are adolescents really risk-takers? Most adults say yes, but the science is starting to say no. Frontiers for Young Minds.  3:3. [full text]

7.   Gilaie-Dotan, S.,+ Tymula, A.,+ Cooper, N., Kable, J., Glimcher, P.W., Levy, I. (2014) Neuroanatomy predicts individual risk attitudes. Journal of Neuroscience, Volume 34, Number 37, September 10, 2014 (+shared first author, featured article) [full text]

6.   Tymula, A., Rosenberg Belmaker, L.A., Ruderman, L., Glimcher, P.W., Levy, I. (2013) Like cognitive function, decision-making across the lifespan shows profound age-related changes. Proceedings of the National Academy of Sciences, Volume 110, Number 42, October 15, 2013 [full text]

5.   Yamada, H.+, Tymula, A.+, Louie, K., Glimcher, P.W. (2013) Thirst-dependent risk preferences in monkeys identify a primitive form of wealth. Proceedings of the National Academy of Sciences, Volume 110, Number 39, September 24, 2013 (+shared first author) [full text]

4.   Großer, J., Reuben, E., Tymula, A. (2013) Political quid pro quo agreements: An experimental study. American Journal of Political Science, Volume 57, Number 3, July 2013, p. 582-597 [full text]

3.   Tymula, A.+, Rosenberg Belmaker, L.A.+, Roy, A., Ruderman, L., Manson, K., Glimcher, P.W., Levy, I. (2012) Adolescents’ risk-taking behavior is driven by tolerance to ambiguity. Proceedings of the National Academy of Sciences 109 (42), October 2012, p. 17135-17140 (+ shared first author) [full text]

2.   Levy, I., Rosenberg-Belmaker, L.A., Manson, K., Tymula, A., Glimcher, P.W. (2012) Measuring the subjective value of risky and ambiguous options using experimental economics and functional MRI methods. Journal of Visualized Experiments (67), September 2012 [full text]

1.   Kuhnen, C., and Tymula, A. (2012) Feedback, self-esteem and performance in organizations. Management Science, 58 (1), January 2012, p. 94-113 [full text]

Other writing

Tymula A. (2016) Financial gamble? My brain made me do it. The Conversation [full text]

Tymula A. (2014) Explainer: neuroeconomics, where science and economics meet. The Conversation [full text]

Book review of After Phrenology: Neural Reuse and the Interactive Brain, Michael L. Anderson. The MIT Press, Cambridge, MA, USA (2014) in Journal of Economic Psychology, Volume 51, December 2015, p. 279–280

Working papers under review

Chung H., Tymula A., Glimcher P. (2017) The Reduction of Ventrolateral Prefrontal Cortex Grey Matter Volume Correlates with Loss of Economic Rationality in Aging, r&r

Yamada H., Louie K., Tymula A. and Glimcher P.W. (2017) Free choice shapes normalized value signals in medial orbitofrontal cortex, r&r

Glimcher, P. W. and Tymula A. (2016) Expected Subjective Value Theory (ESVT): A representation of decision under risk and certainty, r&r

We present a descriptive model of choice with normative foundations based on how the brain is thought to represent value. An individual’s behavior is fully described by two primitives: an individual’s expectation and one free parameter we call “predisposition’. The model captures the same apparent preference phenomena illustrated by Prospect Theory but unlike Prospect Theory accounts for individual heterogeneity in parameters, employs far fewer parameters than full prospect theory, and retains neurobiological plausibility as a causal model of the choice process. Additionally, our theory makes a series of novel predictions amenable to future testing and includes an alternative explanation for endowment effect.

Rosato A. and Tymula A. (2016) Loss Aversion and Competition in Vickrey Auctions: Money Ain’t No Good [full text]

A key prediction of expectations-based reference-dependent preferences and loss aversion in second-price (Vickrey) auctions with private values is that the number of bidders should affect bids in auctions for real objects but not in auctions with induced monetary values. We develop an experiment with a within-subject design aimed at testing this distinctive comparative statics prediction. Our results are consistent with expectations-based reference-dependent preferences and loss aversion. In real-object auctions, we find that subjects’ bids are affected by the number of competitors and, on average, they decline with the intensity of competition. In induced-value auctions, instead, bids are unaffected by the intensity of competition. We also successfully replicate an experiment from Sprenger (2015) aimed at distinguishing expectations-based loss aversion from models of Disappointment Aversion. This provides additional evidence that our findings in the auction experiments are due to expectations-based loss aversion.

Chung, H., Glimcher. P.W., Tymula, A. (2016) An Experimental Comparison of Risky and Riskless Choice – Limitations of Prospect Theory and Expected Utility Theory [full text]

Prospect theory, widely used descriptively for decisions under both risk and certainty, presumes concave utility over “gains” and convex utility over “losses”; a pattern widely seen in lottery tasks. Although such gain-loss asymmetry is also widely used to model riskless choices, limited empirical evidence supports this use. In incentive-compatible experiments we find that in riskless choice gain-loss asymmetries are not observed as predicted by prospect theory even while in the same participants gain-loss asymmetries are observed under risk. Our results imply that utility functions under conditions of certainty can be more closely approximated using neoclassical rather than prospect theoretic preferences.

Tymula, A. and Whitehair, J. (2017) Young adults gamble less when observed by peers [full text]

Presence of observers is often identified as the main factor behind why young adults make welfare-decreasing choices. The mechanism through which others exert this influence is not fully understood. In this paper, using an incentive compatible experiment, we investigate whether: (1) young people’s willingness to accept known and unknown risks changes in the presence of a person of the same age compared to in private and (2) whether preferences are affected by having observed others decisions. We find that contrary to common wisdom young adults do not gamble more when observed by peers, instead they become more ambiguity averse when observed.

Non – traditional research output

1.   Tymula, A. and Glimcher, P.W. (2015) Are Adolescents Really Risk-Takers? Most Adults Say Yes, but the Science is Starting to Say No. Frontiers for Young Minds.3:3. [full text]

– selected to be featured on the Scientific American Blog Network!

2.   Decision-making and ageing exhibit at the Museum of the National Academy of Sciences in Washington, DC (part of the Life Lab exhibit)

– currently on display since May 2012

– don’t miss this exhibit / experiment when you visit Washington!