AMU - AMSE
5-9 Boulevard Maurice Bourdet, CS 50498
13205 Marseille Cedex 1
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Jiakun Zheng


Îlot Bernard du Bois
Publications
101 real couples participated in a controlled experimental risk-taking task involving variations in household and individual income risks, while controlling for ex-ante income inequality. Our design disentangles the effects of household risk, intra-household risk inequality, and ex-post payoff inequality. We find that most couples (about 79%) pooled their risk at the household level when risks were borne symmetrically, but a significant proportion of couples (about 36%) failed to do so when individual risks were borne asymmetrically. Additionally, within the scope of the control variables we have utilized, we find that intra-household risk inequality has a larger impact on non-married couples compared to married ones. These results remain robust when the analysis is limited to couples in which both spouses are risk-averse. Lastly, we find that preferences for household efficiency are significantly correlated across both certain and risky situations. However, couples consisting of two income-maximizing spouses do not show greater aversion to risk inequality compared to couples with other compositions.
Lack of high-quality value per statistical life (VSL) studies in low- and middle-income countries have been recognized by scholars and analysts in the benefit-cost analysis field for decades. However, progress has been slow in addressing it. We estimated VSL in China using a stated-preference survey in the context of reducing mortality risks associated with COVID-19. The survey was administered in seven cities across China in 2022 with a purposive sampling approach, and consistency checks at different levels of stringency regarding willingness to pay (WTP) for mortality risk reductions of different magnitudes were used to screen respondents. The estimated VSL ranges from 8.0 million to 10.3 million Chinese Yuan, which is higher than previous estimates. Also previous studies found much higher VSL estimates from a subsample obtained with more stringent consistency check requiring that WTP be approximately proportional to the magnitude of mortality risk reduction, we did not find such a difference with our dataset. In addition, based on our anlaysis, respondents in first-tier cities such as Beijing, Shanghai and Guangzhou have higher VSL than those in second-tier cities such as Changchun, Chengdu, Wuhan and Xi’an; the VSL-age relationship shows a U-shaped pattern; and the collective experience of city lockdown has a negative impact on VSL. Other factors which were found to influence VSL include education, sector of work, health status, risk perception, behaviors (physical exercises, wearing face masks, getting vaccinated), knowledge, political identity, and trust in government.
JEL classification codes
I12, I18
This paper considers a risk-neutral insurer and a risk-averse individual who bargain over the terms of an insurance contract. Under asymmetric Nash bargaining, we show that the Pareto-optimal insurance contract always contains a straight deductible under linear transaction costs and that the deductible disappears if and only if the deadweight cost is zero, regardless of the insurer's bargaining power. We further find that the optimality of no insurance is consistent across all market structures. When the insured's risk preference exhibits decreasing absolute risk aversion, the optimal deductible and the insurer's expected loss decrease in the degree of the insured's risk aversion and thus increase in the insured's initial wealth. In addition, the effect of increasing the insurer's bargaining power on the optimal deductible is equivalent to a pure effect of reducing the initial wealth of the insured. Our results suggest that the well-documented preference for low deductibles could be the result of insurance bargaining.
Salience theory relies on the assumption that not only the marginal distribution of lotteries, but also the correlation of payoffs across states impacts choices. Recent experimental studies on salience theory seem to provide evidence in favor of such correlation effects. However, these studies fail to control for event-splitting effects (ESE). In this paper, we seek to disentangle the role of correlation and event-splitting in two settings: (1) the common consequence Allais paradox as studied by Bordalo et al. (Q J Econ 127:1243–1285, 2012), Frydman and Mormann (The role of salience in choice under risk: An experimental investigation. Working Paper, 2018), and Bruhin et al. (J Risk Uncertain 65:139–184, 2022); (2) choices between Mao pairs as studied by Dertwinkel-Kalt and Köster (J Eur Econ Assoc 18:2057–2107, 2020). In both settings, we find evidence suggesting that recent findings supporting correlation effects are largely driven by ESE. Once controlling for ESE, we find no consistent evidence for correlation effects. Our results thus shed doubt on the validity of salience theory in describing risky behavior.
We surveyed economists’ attitudes toward adjusting discount rates to the risk profile of public programs. Three-quarters of respondents recommend to use project-specific discount rates. For example, on average, respondents discount railway infrastructures more than hospitals and climate mitigation. But the degree of discount discrimination between distinct risk profiles of different projects is fairly limited in our sample given the differences in risk profiles for these projects. Economic experts thus penalize risky public projects far less than financial markets penalize private investments. We call this the ”discount premium puzzle”. Finally, among experts in favor of a single discount rate, there is no consensus on whether it should be based on the average cost of capital in the economy, the sovereign borrowing cost, or the Ramsey rule, which gives rise to disagreement over the level of the recommended discount rate.
The existing literature in insurance economics has shown that narrow framing can explain why people buy too little insurance compared to what standard theory predicts. However, there is also ample evidence suggesting people sometimes buy too much insurance. In this paper, we assume S-shaped narrow framing, i.e., the local utility function for evaluating the net insurance payoff is convex in the loss domain but concave in the gain domain, and show that it can reconcile with both insurance puzzles simultaneously. Especially, we show the policyholder under S-shaped narrow framing is more likely to underinsure more negatively skewed risks of loss but to overinsure less negatively skewed risks of loss when only coinsurance is offered. We further characterize the optimal insurance scheme under S-shaped narrow framing while incentive compatibility is satisfied. It contains a straight deductible when the net insurance payoff is negative but partial insurance when the net insurance payoff is positive.
In this paper, we study the willingness to pay for reductions in health risks within a framework of anticipated regret. We show that ex post information provision can be a relevant factor for regret theory to account for why people are sometimes so inclined to protect themself against certain types of health risks but not others. In particular, we find that under full resolution of uncertainty disproportionate aversion to large regrets exaggerates willingness to pay estimates. The effect induced by this notion of regret aversion can be interpreted as if regret-averse people overweight risk reductions due to prevention. However, as feedback over forgone acts is missing, the regret aversion effect disappears. Finally, we show that information avoidance induced by regret aversion can significantly bias our evaluation to prefer those health programs that completely eliminate a risk, i.e., the certainty effect.
In this paper, we study insurance decisions when the policyholder evaluates insurance with narrow framing. We show that due to aversion to risk on the net insurance payoff, i.e., insurance indemnity minus insurance premium, narrow framing reduces insurance demand. This helps explaining the observed low insurance demand in many insurance markets. We also show that the optimal insurance contract involves a deductible and the coinsurance of losses above the deductible when transaction costs depend on the actuarial value of the policy. Moreover, when the policyholder is loss averse over the net insurance payoff, a fixed indemnity equal to insurance premium should be paid for a range of intermediate losses.