Leadership in Multi-sided Markets

I analyze the role of leadership in multi-sided markets as online advertising. Search and display advertising are better characterized by (respectively) quantity and price competition. A platform that reached dominance in search may have an incentive to limit services to consumers to be aggressive with the advertisers, to exploit its scale in search to build barriers to entry, or to adopt click-weighted auctions to manipulate the pricing of sponsored links. On the other side, a dominant platform in display advertising may increase the rewards of content providers to increase prices on advertisers, or may adopt exclusive clauses to predate on other platforms.Multisided markets, Leadership, Dominance

An Experimental Analysis of Auctioning Emission Allowances Under a Loose Cap

The direct sale of emission allowances by auction is an emerging characteristic of cap-and-trade programs. This study is motivated by the observation that all of the major implementations of cap-and-trade regulations for the control of air pollution have started with a generous allocation of allowances relative to recent emissions history, a situation we refer to as a “loose cap.†Typically more stringent reductions are achieved in subsequent years of a program. We use an experimental setting to investigate the effects of a loose cap environment on a variety of auction types. We find that all auction formats studied are efficient in allocating emission allowances, but auction revenues tend to be lower relative to competitive benchmarks when the cap is loose. Regardless of whether the cap is tight or loose, the different auction formats tend to yield comparable revenues toward the end of a series of auctions. However, aggressive bidding behavior in initial discriminatory auctions yields higher revenues than in the other auction formats, a difference that disappears as bidders learn to adjust their bids closer to the cut-off that separates winning and losing bids.auction, carbon dioxide, greenhouse gases, allowance trading, Regional Greenhouse Gas Initiative, RGGI, cap and trade, Environmental Economics and Policy, Resource /Energy Economics and Policy,

Bidding Strategies for Proportional Representation in Advertisement Campaigns

Many companies rely on advertising platforms such as Google, Facebook, or Instagram to recruit a large and diverse applicant pool for job openings. Prior works have shown that equitable bidding may not result in equitable outcomes due to heterogeneous levels of competition for different types of individuals. Suggestions have been made to address this problem via revisions to the advertising platform. However, it may be challenging to convince platforms to undergo a costly re-vamp of their system, and in addition it might not offer the flexibility necessary to capture the many types of fairness notions and other constraints that advertisers would like to ensure. Instead, we consider alterations that make no change to the platform mechanism and instead change the bidding strategies used by advertisers. We compare two natural fairness objectives: one in which the advertisers must treat groups equally when bidding in order to achieve a yield with group-parity guarantees, and another in which the bids are not constrained and only the yield must satisfy parity constraints. We show that requiring parity with respect to both bids and yield can result in an arbitrarily large decrease in efficiency compared to requiring equal yield proportions alone. We find that autobidding is a natural way to realize this latter objective and show how existing work in this area can be extended to provide efficient bidding strategies that provide high utility while satisfying group parity constraints as well as deterministic and randomized rounding techniques to uphold these guarantees. Finally, we demonstrate the effectiveness of our proposed solutions on data adapted from a real-world employment dataset.Comment: Foundations of Responsible Computing (FORC 2023

Individual Fairness in Advertising Auctions Through Inverse Proportionality

Recent empirical work demonstrates that online advertisement can exhibit bias in the delivery of ads across users even when all advertisers bid in a non-discriminatory manner. We study the design ad auctions that, given fair bids, are guaranteed to produce fair outcomes. Following the works of Dwork and Ilvento [2019] and Chawla et al. [2020], our goal is to design a truthful auction that satisfies "individual fairness" in its outcomes: informally speaking, users that are similar to each other should obtain similar allocations of ads. Within this framework we quantify the tradeoff between social welfare maximization and fairness. This work makes two conceptual contributions. First, we express the fairness constraint as a kind of stability condition: any two users that are assigned multiplicatively similar values by all the advertisers must receive additively similar allocations for each advertiser. This value stability constraint is expressed as a function that maps the multiplicative distance between value vectors to the maximum allowable ?_{?} distance between the corresponding allocations. Standard auctions do not satisfy this kind of value stability. Second, we introduce a new class of allocation algorithms called Inverse Proportional Allocation that achieve a near optimal tradeoff between fairness and social welfare for a broad and expressive class of value stability conditions. These allocation algorithms are truthful and prior-free, and achieve a constant factor approximation to the optimal (unconstrained) social welfare. In particular, the approximation ratio is independent of the number of advertisers in the system. In this respect, these allocation algorithms greatly surpass the guarantees achieved in previous work. We also extend our results to broader notions of fairness that we call subset fairness

Implementing Fairness Constraints in Markets Using Taxes and Subsidies

Fisher markets are those where buyers with budgets compete for scarce items, a natural model for many real world markets including online advertising. A market equilibrium is a set of prices and allocations of items such that supply meets demand. We show how market designers can use taxes or subsidies in Fisher markets to ensure that market equilibrium outcomes fall within certain constraints. We show how these taxes and subsidies can be computed even in an online setting where the market designer does not have access to private valuations. We adapt various types of fairness constraints proposed in existing literature to the market case and show who benefits and who loses from these constraints, as well as the extent to which properties of markets including Pareto optimality, envy-freeness, and incentive compatibility are preserved. We find that some prior discussed constraints have few guarantees in terms of who is made better or worse off by their imposition

Discrimination by Design?

Platform world is speeding the redesign of employment. Bricks-and-mortar firms once hired through narrow portals and then invested in the workers they hired, providing job security and predictable career ladders. Platform world flings the doors wide open to income-generating efforts, providing new opportunities but also offering security and predictable advancement to almost no one.Other legal scholars have mined these same data for gender disparities; they have found disparities in the platform economy arising from customer biases and individual preferences, and manifested in men’s and women’s different experiences in everything from pricing plumbing services to fraud prevention. Neutral-appearing algorithms may then amplify the impact on wages and opportunities. Because the outcomes are not equal, other scholars argue that these disparities should be actionable. Accordingly, they suggest various ways to adapt existing laws to remedy gender disparities.This Article is the first to develop an analysis of the multiple types of gender disparities in platform world. Rather than focus on the fact that disparities exist, this Article asks the question when—and even more provocatively, whether—they should matter.First, the Article documents the various sources and forms of gender disparities, setting up the argument that no one legal approach fits. Second, while some of those disparities are already actionable under existing antidiscrimination laws, even antidiscrimination law today rarely provides a viable cause of action simply because the results produce statistical disparities. In platform world, it’s not clear that the disparities are morally questionable, actionable under existing law, or appropriate subjects for regulation. The real issues in this new economy concern the lack of benefits, stability, and promotion opportunities. Antidiscrimination law can help those employed by platform companies, but not the gig workers who need health benefits and protection against harassment, nor the algorithms that need oversight. Consequently, existing antidiscrimination law is all but irrelevant except to address the most glaring discrepancies, and the real need is for a wholesale rethinking of the legal infrastructure necessary to realize the benefits of the platform economy for more than a few platform creators