Periodic Reporting for period 1 - IMD (Inequality-aware Market Design)
Reporting period: 2022-07-01 to 2024-12-31
In this project, we challenge this conventional wisdom and explore the optimal design of marketplaces in the presence of underlying inequalities, leading to a theory of Inequality-aware Market Design (IMD). Our theory is based on two fundamental premises. First, the policymaker is concerned about the welfare of the most disadvantaged market participants. To capture that, we introduce welfare weights that reflect the redistributive goals of the policymaker. Second, market participants have private information both about their preferences and their level of need. In other words, the policymaker cannot easily identify those most in need and must instead design the rules of the market to ensure that no one is left behind.
The core of the project is to study various market designs from the perspective of efficiency and equity. Our objective is to improve the understanding of optimal policy in such an environment. When is it preferred to let the market decide about the allocation of scarce resources, and when is a government intervention justified? Are in-kind transfers ever preferred to cash transfers? Should we introduce price caps or queues? Are such instruments made redundant by progressive income taxation?
By answering these questions, IMD provides novel solutions to the acute problem of inequality. We explore the connections between market design and public finance to clarify the interaction between various redistributive policies. We aim to provide researchers and policymakers with an effective framework for thinking about the equity-efficiency trade-off in market-design settings.
You can read more about the IMD project here: https://grape.org.pl/project/inequality-aware-market-design#info(opens in new window).
One of the first papers in the IMD agenda presents the baseline IMD framework: A policymaker allocates a set of resources of heterogeneous quality to agents differing in their preferences and level of need. The policymaker only observes an imperfect signal about these parameters and attempts to maximize the overall welfare of the population. We show that a non-market mechanism (allocating the resources at prices that are lower than the market-clearing price) can be optimal in two cases. First, if the designer can identify a group of agents with a high level of need but giving a cash transfer to these agents is impossible (e.g. due to political reasons), it may be optimal to effect redistribution to that group via in-kind transfers. Second, if there is strong and negative statistical association between willingness to pay and the level of need (e.g. if demand is driven mostly by wealth and not the true level of need), it may be optimal to offer low qualities of the good at below-market prices. These results help explain why free provision of basic health care may be a good idea, while controlling prices of most everyday consumption goods is probably not.
Our approach offers novel insight into the age-old challenge in economics: balancing equity and efficiency. In applications, we show that the prescriptions of our theory often differ from conventional wisdom and offer valuable guidelines to policymakers. In a paper about the optimal allocation of vaccines during a pandemic, we demonstrated that—while a market mechanism for vaccines would be inefficient and inequitable—an improvement can nevertheless be made by using prices in limited circumstances. In an article studying electricity prices, we pointed out that a uniform price cap on energy is regressive: It gives a higher effective subsidy to those who consume the most—typically the relatively wealthy consumers. A better policy is to offer a subsidized price for relatively low levels of consumption and increase the price for units consumed above a certain threshold.
In ongoing work, we investigate the optimal interaction between market-level policies and income taxation. We derived conditions under which income taxes alone are sufficient; next, we will explore cases when market interventions are required to complement the redistribution toolset of the policymakers.
From a methodological perspective, we contributed to the theory of mechanism design by introducing unobserved social welfare weights to the canonical framework. The presence of welfare weights ushered in a number of technical challenges, and we extended existing techniques to handle them. This allowed us to offer a wide range of novel economic insights about the equity-efficiency trade-off.
Going forward, we want to develop a deeper understanding of how IMD interacts with income taxation. Even though our existing work demonstrates that income taxation does not render IMD obsolete, we must still address the question of how to optimally combine these tools. The question comes with its own technical challenges because studying income taxation together with market design requires a rich model of behavior. We are currently building a tractable framework to address those challenges and derive policy implications. In addition, we will study extensions accounting for various real-life constraints and considerations.