Deciding about human lives: an experimental measure of risk attitudes under prospect theory


Social Choice and Welfare

juin 2018, vol. 51, n°1, pp.163-192

Départements : Economie et Sciences de la décision, GREGHEC (CNRS)

For public policies in the health, security or safety domains, the main consequences concern the number of human lives that are saved or lost, and are uncertain ex-ante. In classic economic evaluations of such policies, losses and gains of human lives are often monetized and aggregated with other costs and benefits. Uncertainty about human lives is thus treated as uncertainty about monetary consequences. In this paper, we question whether people risk human lives as they risk money.We present an experiment comparing risk attitudes towards human lives and towards money under prospect theory. The results show that respondents treat the two attributes differently when losses are involved. Specifically, the decisions involving human lives are characterizedby less elevated probability weighting in the loss domain and higher loss aversion compared to decisions involving money. These findings suggest that public preferences may differ from the cost-benefit analysis recommendations

Decision Theory Made Relevant: Between the Software and the Shrink


Research in Economics

juin 2018, vol. 72, n°2, pp.240-250

Départements : Economie et Sciences de la décision, GREGHEC (CNRS), Stratégie et Politique d’Entreprise

Decision theory offers a formal approach to decision making, which is often viewed and taught as the rational way to approach managerial decisions. Half a century ago it generated high hopes of capturing and perhaps replacing intuition, and providing the “right” answer in practically all managerial situations. Today it seems fair to say that decision theory has not lived up to these expectations. Behavioral science provides ample evidence that managers fail to follow the dicta of decision theory, even when these are explained to them. As a result, executives often find decision theory frustrating and useless and prefer to rely on their intuition. This paper suggests that this extreme conclusion is unwarranted and calls for a re-appraisal of decision theory. We propose that it should not always be regarded as a mathematical tool that produces the answer; rather, it can be viewed as a framework for a dialog between the decision maker and the decision theorist. In one extreme, the decision theorist studies the problem and provides the “correct’’ answer. But in another, the decision theorist only challenges the decision maker’s intuition and logic. In between, a whole gamut of possible dialogs exists, in which decision theory doesn’t replace intuition, but supports and refines it

Dynamic Atomic Congestion Games with Seasonal Flows


Operations Research

mars-avril 2018, vol. 66, n°2, pp.327-339

Départements : Economie et Sciences de la décision, GREGHEC (CNRS)

Mots clés : network games, dynamic flows, price of anarchy, price of stability, Braess ratio, max-flow min-cut

We propose a model of discrete time dynamic congestion games with atomic players and a single source-destination pair. The latencies of edges are composed by free-flow transit times and possible queuing time due to capacity constraints. We give a precise description of the dynamics induced by the individual strategies of players and of the corresponding costs, either when the traffic is controlled by a planner, or when players act selfishly. In parallel networks, optimal and equilibrium behavior eventually coincides, but the selfish behavior of the first players has consequences that cannot be undone and are paid by all future generations. In more general topologies, our main contributions are three-fold. First, we show that equilibria are usually not unique. In particular, we prove that there exists a sequence of networks such that the price of anarchy is equal to n-1, where n is the number of vertices, and the price of stability is equal to 1.Second, we illustrate a new dynamic version of Braess's paradox: the presence of initial queues in a network may decrease the long-run costs in equilibrium. This paradox may arise even in networks for which no Braess's paradox was previously known.Third, we propose an extension to model seasonalities by assuming that departure flows fluctuate periodically over time. We introduce a measure that captures the queues induced by periodicity of inflows. This measure is the increase in costs compared to uniform departures for optimal and equilibrium flows in parallel networks

Economics: Between prediction and criticism


International Economic Review

mai 2018, vol. 59, n°2, pp.367-390

Départements : Economie et Sciences de la décision, GREGHEC (CNRS)

We suggest that one way in which economic analysis is useful is by offering a critique of reasoning. According to this view, economic theory may be useful not only by providing predictions, but also by pointing out weaknesses of arguments. It is argued that, when a theory requires a non‐trivial act of interpretation, its roles in producing predictions and offering critiques vary in a substantial way. We offer a formal model in which these different roles can be captured

Honoring Sovereign Debt or Bailing Out Domestic Residents? The Limits to Bailouts


Journal of International Economics

septembre 2018, vol. 114, pp.14-24

Départements : Economie et Sciences de la décision

Mots clés : Sovereign debt, Internal cost of default, Bailouts

Why does a borrowing country not avoid the internal cost of default, an important driver of sovereign debt repayment, by implementing domestic sector bailouts? This paper investigates sovereign debt sustainability in a model where domestic and foreign investors optimally select their portfolios and the sovereign decides over its default and bailout policies. It shows that internal bailouts do not preclude sovereign borrowing when domestic private exposures to sovereign debt, direct or indirect, cannot be observed or inferred by the sovereign. In equilibrium, when these exposures are correlated with future liquidity needs, bailouts are less efficient to compensate domestic losses making repayment more desirable. “Opacity" on financial exposures is then a commitment device for sovereigns to honor their debts and thus may be welfare improving

Risk Versus Ambiguity and International Security Design


Journal of International Economics

juillet 2018, vol. 113, pp.74-105

Départements : Economie et Sciences de la décision, GREGHEC (CNRS)

Mots clés : Ambiguity aversion; Risk aversion; Debt/equity choice; International capital flows; International insurance; Home bias

We study portfolio allocation and characterize contracts issued by firms in the international financial market when investors exhibit ambiguity aversion and perceive ambiguity in assets issued in foreign locations. Increases in the variance of their risky production process cause firms to issue assets with a higher variable payment (equity). Hikes in investors’ perceived ambiguity have the opposite effect, and lead to less risk-sharing. Entrepreneurs from capital-scarce countries finance themselves relatively more through debt than equity. They are thus exposed to higher volatility per unit of consumption. The expected returns on capital invested in capital-scarce countries may also be lower. Such results do not hold in the absence of ambiguity, that is, when investors only perceive risk. New facts uncovered from cross-country firm-level data are consistent with our model

Bref addendum sur la « conception expérimentale de la rationalité »


Revue Economique

avril 2017, vol. 68, pp.701-703

Départements : Economie et Sciences de la décision, GREGHEC (CNRS)

Un article précédent défendait, en l’attribuant à Allais et à ses successeursMacCrimmon et Larsson, une conception inédite qui recommanderait d’étudiersur des données de comportement non seulement la conformité des individusaux règles normatives, mais encore la normativité même de ces règles. Cet article a suscité de la part de Dorian Jullien des commentaires auxquels nous répondons ici

Characterizations of Smooth Ambiguity Based on Continuous and Discrete Data


Mathematics of Operations Research

février 2017, vol. 42, n°1, pp.167-178

Départements : Economie et Sciences de la décision

Mots clés : smooth ambiguity; variational preferences; revealed preference; completely monotone functions; Afriat inequalities; moment problem

In the Anscombe-Aumann setup, we provide conditions for a collection of observations to be consistent with a well-known class of smooth ambiguity preferences (Klibanoff P, Marinacci M, Mukerji S (2005) A smooth model of decision making under ambiguity. Econometrica 73(6):1849–1892.). Each observation is assumed to take the form of an equivalence between an uncertain act and a certain outcome. We provide three results that describe these conditions for data sets of different cardinality. Our findings uncover surprising links between the smooth ambiguity model and classic mathematical results in complex and functional analysis.

Climate Change Assessments: Confidence, Probability, and Decision


Philosophy of Science

juillet 2017, vol. 84, n°3, pp.500-522

Départements : Economie et Sciences de la décision, GREGHEC (CNRS)

The Intergovernmental Panel on Climate Change has developed a novel framework for assessing and communicating uncertainty in the findings published in its periodic assessment reports. But how should these uncertainty assessments inform decisions? We take a formal decision-making perspective to investigate how scientific input formulated in the IPCC’s novel framework might inform decisions in a principled way through a normative decision model

Gross, net, and new job creation by entrepreneurs


Journal of Business Venturing Insights

novembre 2017, vol. 8, pp.64-70

Départements : Economie et Sciences de la décision, GREGHEC (CNRS)

Mots clés : EntrepreneurshipJob creationIncorporationOccupational choiceSelf-employmentSole proprietorship

Using a dataset with over 24 million year-employment observations and the universe of more than 230,000 entries into entrepreneurship in one economy we analyze the gross (including the founders), net (excluding the founders), and new (jobs to the former unemployed or those outside the labor force) job creation by entrepreneurs two and six years after start-up. These novel measures of job creation show that the average entrepreneur does not create any jobs for any other than him/her-self, and typically arrives from having another job. Thus, short term job creation by entrepreneurs involves a reshuffling of jobs from older to new firms rather than creating new jobs