INTRODUCTION

I'll post market design related news and items about repugnant markets. See also my Stanford profile. I have a general-interest book on market design: Who Gets What--and Why The subtitle is "The new economics of matchmaking and market design."
Payday loans and other expensive services to those without access to formal credit generate a good deal of repugnance and regulation (including bans), but may be the only source of credit available to their habitual customers. Here's a new NBER working paper on that finds that experienced borrowers don't misjudge their chances of borrowing again.
Are High-Interest Loans Predatory? Theory and Evidence from Payday Lending by Hunt Allcott, Joshua J. Kim, Dmitry Taubinsky & Jonathan Zinman WORKING PAPER 28799, DOI 10.3386/w28799, May 2021
Abstract: It is often argued that people might take on too much high-cost debt because they are present focused and/or overoptimistic about how soon they will repay. We measure borrowers' present focus and overoptimism using an experiment with a large payday lender. Although the most inexperienced quartile of borrowers underestimate their likelihood of future borrowing, the more experienced three quartiles predict correctly on average. This finding contrasts sharply with priors we elicited from 103 payday lending and behavioral economics experts, who believed that the average borrower would be highly overoptimistic about getting out of debt. Borrowers are willing to pay a significant premium for an experimental incentive to avoid future borrowing, which we show implies that they perceive themselves to be time inconsistent. We use borrowers' predicted behavior and valuation of the experimental incentive to estimate a model of present focus and naivete. We then use the model to study common payday lending regulations. In our model, banning payday loans reduces welfare relative to existing regulation, while limits on repeat borrowing might increase welfare by inducing faster repayment that is more consistent with long-run preferences.
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Update: here's the published paper
Allcott, Hunt, Joshua Kim, Dmitry Taubinsky, and Jonathan Zinman. "Are high-interest loans predatory? theory and evidence from payday lending." The Review of Economic Studies 89, no. 3 (2022): 1041-1084.
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Are paid plasma donors being exploited? Here's a paper that suggests not, but rather that the payments that plasma donors receive can improve their financial well being not merely by providing additional income, but also by helping them avoid going into expensive debt.
Dooley, John and Emily Gallagher, Blood Money (October 11, 2021). Available at SSRN: https://ssrn.com/abstract=3940369 or http://dx.doi.org/10.2139/ssrn.3940369
Abstract: "Little is known about the motivations and outcomes of sellers in remunerated markets for human materials. We exploit dramatic growth in the number of commercial blood plasma centers in the U.S. to study the individuals who sell plasma. We find sellers tend to be young and liquidity constrained with low incomes and credit scores; they also report less access to traditional bank credit. Plasma centers absorb demand for non-traditional credit. The opening of a nearby plasma center reduces payday loan inquires and transactions by 13–18% among young borrowers. Meanwhile, foot traffic increases by over 9% at both essential and non-essential goods establishments when a new plasma center opens nearby. Our findings suggest that, at least in the short-term, constrained households use the discretionary income from plasma centers to smooth consumption without appealing to high-cost debt."
HT: Mario Macis
Update: here's the published version
John M Dooley, Emily A Gallagher, Blood Money: Selling Plasma to Avoid High-Interest Loans, The Review of Financial Studies, 2024; https://doi.org/10.1093/rfs/hhae018