Two-sided reputation in certification markets

We consider a market where privately informed sellers resort to certification to overcome adverse selection. There is uncertainty about the certifier's ability to generate accurate information. The profit of a monopolistic certifier is an inverted U-shaped function of his reputation for accuracy: being perceived as more precise allows to attract more good sellers but a high expected precision also deters bad sellers. Since the certifier tries to reach a balanced reputation to attract both types, reputation has a disciplining effect when the certifier is perceived as insufficiently accurate, but gives incentives to decrease precision when he is perceived as “too" accurate. The impact of competition depends on whether sellers “multihome" or “singlehome". Under singlehoming, certifiers compete to attract good sellers, which makes higher reputation more valuable. Multihoming makes higher reputations less desirable because the competitor exerts a negative externality by providing extra information. Therefore, singlehoming attenuates bad reputation effects, while multihoming exacerbates inefficiencies

Transparency in the financial system: rollover risk and crises

The paper presents a theory of optimal transparency in the financial system when financial institutions have short-term liabilities and are exposed to rollover risk. Our analysis indicates that transparency enhances the stability of the financial system during crises but may have a destabilizing effect during normal economic times. Thus, the optimal level of transparency is contingent on the state of the economy, with the regulator increasing disclosure in times of crises. Under this policy, however, an increase in disclosure signals a deterioration of the economy's fundamentals, so the regulator has incentives to withhold information ex-post. In that case, the regulator may have to commit ex-ante to a degree of transparency which trades off the frequency and magnitude of financial crises. The analysis also considers the possibility that financial institutions, in an attempt to deal with rollover risk, either diversify their risks or increase the liquidity of their balance sheets

The blockchain folk theorem

Blockchains are distributed ledgers, operated within peer-to-peer networks. If reliable and stable, they could offer a new, cost effective way to record transactions, but are they? We model the proof-of-work blockchain protocol as a stochastic game and analyse the equilibrium strategies of rational, strategic miners. Mining the longest chain is a Markov perfect equilibrium, without forking, in line with Nakamoto (2008). The blockchain protocol, however, is a coordination game, with multiple equilibria. There exist equilibria with forks, leading to orphaned blocks and persistent divergence between chains. We also show how forks can be generated by information delays and software upgrades. Last we identify negative externalities implying that equilibrium investment in computing capacity is excessive

The blockchain folk theorem

Blockchains are distributed ledgers, operated within peer-to-peer networks. If reliable and stable, they could offer a new, cost effective way to record transactions, but are they? We model the proof-of-work blockchain protocol as a stochastic game and analyse the equilibrium strategies of rational, strategic miners. Mining the longest chain is a Markov perfect equilibrium, without forking, in line with Nakamoto (2008). The blockchain protocol, however, is a coordination game, with multiple equilibria. There exist equilibria with forks, leading to orphaned blocks and persistent divergence between chains. We also show how forks can be generated by information delays and software upgrades. Last we identify negative externalities implying that equilibrium investment in computing capacity is excessive

Fair cost sharing: big tech vs telcos

We study a cost-sharing mechanism where a content provider contributes to covering the costs incurred by a network operator when delivering content to consumers. The costshare not only boosts the content provider's incentives to moderate trac but also aects the price composition for consumers buying access and content. We show the overall eect on consumer welfare depends on the content provider's ability to monetize users. When that ability is high, introducing a cost-share can lead to lower overall prices and higher consumer welfare. We study the robustness of this result to long-term investments in cost reduction by the operator and to heterogeneity in consumers' taste for content. In extensions with multiple contents and multiple operators, contractual externalities arise that suggest a role for regulation

Equilibrium bitcoin pricing

We offer an overlapping generations equilibrium model of cryptocurrency pricing and confront it to new data on bitcoin transactional benefits and costs. The model emphasizes that the fundamental value of the cryptocurrency is the stream of net transactional benefits it will provide, which depend on its future prices. The link between future and present prices implies that returns can exhibit large volatility unrelated to fundamentals. We construct an index measuring the ease with which bitcoins can be used to purchase goods and services, and we also measure costs incurred by bitcoin owners. Consistent with the model, estimated transactional net benefits explain a statistically significant fraction of bitcoin returns

Equilibrium bitcoin pricing

We offer an overlapping generations equilibrium model of cryptocurrency pricing and confront it to new data on bitcoin transactional benefits and costs. The model emphasizes that the fundamental value of the cryptocurrency is the stream of net transactional benefits it will provide, which depend on its future prices. The link between future and present prices implies that returns can exhibit large volatility unrelated to fundamentals. We construct an index measuring the ease with which bitcoins can be used to purchase goods and services, and we also measure costs incurred by bitcoin owners. Consistent with the model, estimated transactional net benefits explain a statistically significant fraction of bitcoin returns

Lending and monitoring: Big Tech vs Banks

We show that by lending to merchants and monitoring them, an e-commerce platform can price-discriminate between merchants with high and low financial constraints: the platform offers credit priced below market rates and designed to select merchants with lower capital or collateral while simultaneously increasing the platform’s access fees. The credit market then becomes endogenously segmented with banks focusing on less financially constrained borrowers. Lending by the platform expands with its monitoring efficiency but can arise even when the platform is less efficient than banks at monitoring. Platform credit benefits more financially constrained merchants as well as buyers, but can hurt less financially constrained merchants if cross-side network effects with buyers are too small. The platform’s propensity to offer credit and the financial inclusion of more constrained merchants depends on the platform’s market power

Mobile Payments and Interoperability: Insights from the Academic Literature

We connect various streams of academic literature to shed light on how the degree of interoperability in mobile payments affects market outcomes and welfare. We organize our discussion around four dimensions of interoperability. First, we consider mobile network interoperability (whether clients of one telecom can access another telecom’s payment services) in connection with the IO literature on tying. Second, we discuss platform level interoperability (the ability to send money offnetwork) in light of the literature on compatibility. We also build on the behavioral IO literature to suggest how the effects of interoperability may be very heterogeneous across various types of firms and consumers, or even backfire. Third, we consider interoperability in the cash-in-cash-out agent network, in light of the literature on co-investment in network industries, and of more specific studies on ATMs’ interoperability. Fourth, we discuss how the literature in banking and on data ownership can be used to understand interoperability of data. We conclude with some broader remarks on policy implications and on possible directions for future research

Equilibrium Bitcoin Pricing

We offer an overlapping generations equilibrium model of cryptocurrency pricing and confront it to new data on bitcoin transactional benefits and costs. The model emphasizes that the fundamental value of the cryptocurrency is the stream of net transactional benefits it will provide, which depend on its future prices. The link between future and present prices implies that returns can exhibit large volatility unrelated to fundamentals. We construct an index measuring the ease with which bitcoins can be used to purchase goods and services, and we also measure costs incurred by bitcoin owners. Consistent with the model, estimated transactional net benefits explain a statistically significant fraction of bitcoin returns