David Ong

Income Attraction: An Online Dating Field Experiment

We measured gender differences in preferences for mate income ex-ante to interaction (“income attraction”) in a field experiment on one of Chinas largest online dating websites. To rule out unobserved factors correlated with income as the basis of attraction, we randomly assigned income levels to 360 artificial profiles and recorded the incomes of nearly 4000 “visits” to full versions of these profiles from search engine results, which displayed abbreviated versions. We found that men of all income levels visited our female profiles of different income levels at roughly equal rates. In contrast, women of all income levels visited our male profiles with higher incomes at higher rates. Surprisingly, these higher rates increased with the womens own incomes and even jumped discontinuously when the male profiles’ incomes went above that of the womens own. Our male profiles with the highest level of income received 10 times more visits than the lowest. This gender difference in ex-ante preferences for mate income could help explain marriage and spousal income patterns found in prior empirical studies.

The gender difference in the value of winning

We design an all-pay auction experiment in which we reveal the gender of the opponent. Using this design, we find that women bid higher than men, but only when bidding against other women. These findings, interpreted through a theoretical model incorporating differences in risk attitude and the value of winning, suggest that women have a higher value of winning than men.

Competition Between and Within Universities: Theoretical and Experimental Investigation of Group Identity and the Desire to Win

We study how salient group identity, created through competition between students from different universities, as well as differences in the value of winning impact competitive behavior. Our experiment employs a simple all-pay auction within and between two university subject pools. We find that when competing against their peers, students within the lower tier university bid more aggressively than students within the top-tier university. Also, students from the lower tier university, in particular women, bid more aggressively when competing against students from the top-tier university. These findings, interpreted through a theoretical model incorporating both group identity and differential value of winning, suggest that students at the lower tier university have a stronger group identity as well as higher desire to win.

Pro Bono Work and Trust in Expert Fields

A controversy has been simmering in law for at least 30 years about whether pro bono work should be mandatory for lawyers, who now donate 1-3% of their time to the poor. This has centered on the unmet legal needs of the poor, the duty of lawyers, and the contrast with US doctors, who are conspicuous in their tradition of voluntary pro bono work. In 2003 alone, they donated

Deserving Altruism: An Experiment in Pure Indirect Reciprocity

12 billion of labor amounting to 5-10% of their time. This debate has tended to neglect the credence good aspect of the services of experts (e.g., of doctors, lawyers, and accountants), and the role that voluntary pro bono work might play. Expert services have un- verifiable quality to non-experts and are subject to moral hazard. Experts who cheat their customers should crowd out experts who do not, resulting in low trust, prestige, and wages. We ask how pro bono work might promote trust in expert fields. We introduce incomplete information into a psychological game theoretic model of experts who value the esteem from their customers. In our model, pro bono work arises in equilibrium because experts who value the perception of honesty among their customers more are also more willing to give away labor to the poor to signal their honesty. We show that if the aversion to disappointing this esteem is sufficiently high, there is a unique equilibrium in which their wages are high, they do pro bono work, and experts who would have been dishonest are crowded out of the field. Our novel approach involving psychological factors suggests that while mandatory pro bono could redistribute surplus from experts to the poor, it could also undermine the screening effect of pro bono work, and thus, cause a deterioration in service quality.

Education and income attraction: an online dating field experiment

Evidence for positive reciprocity, where subjects give more than dictators with the same endowment, has always been rare. We investigate the significant positive reciprocity in a prior experiment which broke a trust game into a 2-stage dictator game. There, the 2nd dictator knew that the 1st dictator was not told of the possibility of reciprocation. We conjectured that the positive reciprocity was the result of the 1st dictators’ revealing their “altruism type.” We predicted that this “type preference” based reciprocity of the 2nd dictator would also be expressed through the indirect reciprocity of an observing 3rd dictator. To test this, we introduced 3rd dictators, again unknown to the 1st dictators, who could now give part of their exogenous endowments to the 1st dictators after observing the 1st dictators’ giving to the 2nd dictators. We used variation in payment schemes to make the announcement of the “last round” credible to 3rd dictators. We found that the 3rd dictators’ giving to the 1st dictators was significantly correlated with the 1st dictators’ giving to the 2nd dictators, controlling for their endowments. To our knowledge, our double-blind design with silent exiting and exogenous endowment is the first to separate “pure” indirect reciprocity from possible inequity aversion, shame, guilt, social influence, efficiency, and experimenter demand effects. Our results suggest that indirect reciprocity is weaker than direct reciprocity. We show evidence for a previously hypothesized demand effect of explicit over implicit double-blindness, but only for the lowest level of endowment.

Choice Overload and Sampling Risk: A Field Experiment with Actual Shoppers

ABSTRACT Prior studies have found a robust correlation in the education of dating and married couples. However, there is little evidence to suggest that such correlations are causal, that is, for the sake of relationship public goods such as the pleasures of the enlightened conversations that only a common high level of education might support. Being empirical studies, they cannot rule out couples matching on other characteristics like income, height or health, which are correlated with education, from driving results. We contribute to this literature by randomly assigning high and low education and income levels to 388 artificial male and female profiles on a large online dating website in China. We then counted thousands of ‘visits’ – clicks on abbreviated profiles, which included education and income information, from search engine results. We found that men’s visits to female profiles were unaffected by the profile’s assigned education level, while women’s visits to male profiles increase with the profile’s education. However, that increase was not increasing on the women’s own level of education, though their visits to the higher income male profiles was increasing on their own education. Our findings suggest that the relationship public goods that stem from a common level of high education are not at the forefront of either men’s or women’s minds before their first dates, when one might expect such goods to play a critical role in the decision to develop the relationship further.

Separating Gratitude from Guilt in the Laboratory

A large body of research has attempted to demonstrate that people can exhibit psychological choice overload behavior (COB) when faced with many choices. However, meta-analyses of these studies (which are of a small number of individual product lines) reveal conflicting results. Findings of COB with some products lines are balanced by findings of choice loving behavior (CLB) with other products. The mean effect across product lines is zero. We hypothesize that COB is driven by ex-ante beliefs of unfamiliar shoppers about the risk of getting an ex-post undesired product. We constructed a measure of sampling risk by surveying 1,440 shoppers for their “likes”, “neutrals”, “dislikes”, and “tried” for 339 varieties across 24 product lines at a large supermarket. We then recorded 35,694 shoppers’ pass bys, stops, or purchases after we randomly reduced the varieties they faced on shelves. Again, the mean effect of reduced varieties across product lines was zero. However, we show that both the probability and intensity of COB/CLB across product lines is predicted by our measure of sampling risk. Our findings are consistent with consumers adjusting a “portfolio” of anticipated nonmonetary returns when facing the greater dispersion of potential outcomes signaled by greater variety.

Fishy Gifts: Bribing with Shame and Guilt

In contrast to guilt based reciprocity, which hypothesizes that reciprocity is an increasing function of the 2nd order expectation of the trustors’ 1st order expectations for reciprocation, we tested for reciprocity that is a decreasing function of the trustees’ 2nd order expectations, i.e., people can reciprocate out of gratitude. To unambiguously decrease the 2nd order expectations in our treatment, we broke up a standard trust game into a two-stage dictator game where the 1st round dictators were not informed about the possibility of a 2nd round. Furthermore, the 2nd dictators could “silently exit” by not sending anything to the 1st round dictators. We found a significant increase in both the amount of reciprocation and the number of people reciprocating as compared to our standard trust and dictator games controls. Most 2nd dictators became poorer than 1st dictators so inequality aversion can be ruled out. We found support for our hypothesis in the prior data of others who tested for guilt based reciprocity. Our result also seems to reconcile conflicting results in that literature. To our knowledge, this is the first paper which shows that kindness distinct from guilt, shame, efficiency, and inequity aversion could be a motive for reciprocity. Our strong positive reciprocity result also suggests why it has been difficult to find in the past.