Christian Catalini


  Friday, July 09, 09:30 - 10:25

From cryptocurrencies, stablecoins and Diem to CBDCs     [Video]


The talk will provide an overview of the evolving cryptocurrency, stablecoin and CBDC landscape, and focus on the economics of the technology and some of the core trade-offs it involves. It will also cover the economic Design of Diem and the implications the network may have on competition and innovation in payments and financial services.

Jing Chen

Stony Brook University

  Saturday, July 10, 13:30 - 14:10

Maximal Information Propagation via Lotteries     [Video]


Propagating information to more people through their friends is becoming an increasingly important technology used in domains such as blockchain, advertising, and social media. To incentivize people to broadcast the desired information, the designer may use a (monetary) rewarding scheme, which specifies who gets how much, to compensate for the propagation. Several properties are desirable for the rewarding scheme, such as budget feasible, individually rational, incentive compatible and Sybil-proof. In this work, we design a free market with lotteries, where every participant decides how much of the reward she wants to withhold before propagating to others. We show that under our scheme, all agents will maximally propagate and all above properties are satisfied.

Andrea Civelli

University of Arkansas

  Friday, July 09, 14:15 - 14:55

Practical Considerations When Issuing Central Bank Digital Currencies    [Video]


Several models have been proposed for retail Central Bank Digital Currencies (CBDC). However, the implementations, proofs of concept, and feasibility studies so far seem to largely favor hybrid/intermediated models. This talk briefly describes the hybrid/intermediated CBDC models and compares them with other architectures. It then discusses some of the practical differences and implications of these two models, especially focusing on the policy and governance trade-offs faced by Central Banks when adopting a CBDC. While some architectural choices are mostly determined by the objectives a Central Bank may want to achieve with a CBDC, there are interesting issues that still need to find practical solutions.

Xiaotie Deng

Peking University

  Saturday, July 10, 09:30 - 10:10

Provable Reputation-based Mechanism Design for Permissioned Blockchains     [Video]


Permissioned blockchains take more reliability on participants than permissionless ones. Considering permissioned blockchains, consisting of three types of participants: providers, collectors, and governors. Providers collect transactions from terminals and forwarded them to collectors; collectors upload received transactions to governors after verifying and labeling them; and governors validate part of the labeled transactions they received, pack valid ones into a block, and append new blocks to the ledger.

To reduce the loss of the governor's transaction verification, we design a reputation protocol to help the governor measure the reliability of collectors, who may behave maliciously. Based on the reputation of collectors, governors can pack high quality transactions from reliable collectors into blocks, effectively decreasing the loss of verifying transactions.

Darrell Duffie

Stanford University

  Friday, July 09, 13:30 - 14:10

Global Implications of China's Central Bank Digital Currency     [Video]


China is introducing a CBDC, called eCNY, whose potential impact on global payments has generated much speculation. This talk will review the nature of eCNY and its key potential global implications.

Ravi Jagadeesan

Stanford University

  Saturday, July 10, 14:15 - 14:55

Markets for Crypto Tokens, and Security under Proof of Stake

(joint work with Christian Catalini and Scott Duke Kominers)


Cryptocurrency systems based on proof of stake (PoS) grant governance rights to the holders of currency tokens and therefore are vulnerable to attack by adversaries who buy tokens in order to gain control. To evaluate the robustness of PoS cryptocurrencies to such attacks, we model the market for tokens and determine how the cost of attacking the system depends on the level and shape of token supply and demand. We show that, contrary to popular belief, the appreciation of tokens in response to demand by attackers plays a small role in securing the system. In particular, stablecoins can be less vulnerable to attack than cryptocurrencies that are freely floating. Moreover, PoS cryptocurrencies that primarily function as mediums of exchange are vulnerable to attack if the velocity of money is high.

Silvio Micali


  Friday, July 09, 15:00 - 15:40

Pure proof of stake: a key to decentralization     [Video]

Georgios Piliouras

Singapore University of Technology and Design (SUTD)

  Saturday, July 10, 10:15 - 10:55

Dynamical Analysis of the EIP-1559 Ethereum Fee Market     [Video]

(joint work with Stefanos Leonardos, Barnabé Monnot, Daniël Reijsbergen and Stratis Skoulakis)


Participation in permissionless blockchains results in competition over system resources, which needs to be controlled with fees. Ethereum's current fee mechanism is implemented via a first-price auction that results in unpredictable fees as well as other inefficiencies. EIP-1559 is a recent, improved proposal that introduces a number of innovative features such as a dynamically adaptive base fee that is burned, instead of being paid to the miners. Despite intense interest in understanding its properties, several basic questions such as whether and under what conditions does this protocol self-stabilize have remained elusive thus far.

We perform a thorough analysis of the resulting fee market dynamic mechanism via a combination of tools from game theory and dynamical systems. We start by providing bounds on the step-size of the base fee update rule that suffice for global convergence to equilibrium via Lyapunov arguments. In the negative direction, we show that for larger step-sizes instability and even formally chaotic behavior are possible under a wide range of settings. We complement these qualitative results with quantitative bounds on the resulting range of base fees. We conclude our analysis with a thorough experimental case study that corroborates our theoretical findings.

Linda Schilling

École Polytechnique CREST

  Friday, July 09, 11:15 - 11:55

Central Bank Digital Currency: When Price and Bank Stability Collide     [Video]


With the introduction of a central bank digital currency or CBDC, the central bank needs to confront classic issues of banking, i.e. the tension between providing liquid means of payments and desirable maturity transformation. We analyze these issues in a nominal version of a Diamond and Dybvig (1983) model, when the central bank additionally has a price stability objective. While the central bank can always deliver on its nominal obligations, central bank runs can occur, manifesting themselves either as excessive real asset liquidation or as a failure to maintain price stability. We demonstrate an impossibility result that we call the CBDC trilemma: of the three goals of efficiency, financial stability (i.e., absence of runs), and price stability, the central bank can achieve at most two.

Andreas Veneris

University of Toronto

  Friday, July 09, 10:30 - 11:10

Central Bank Digital Loonie: Canadian Cash for a New Global Economy     [Video]


Global economic digitization in the IoT/5G-and-beyond/AI era continues to advance at exponential speed. This development is in sharp contrast to the financial sector as payment systems still operate on legacy infrastructure that lacks the flexibility to serve those technology needs. Further, the emergence of Decentralized Finance demonstrates the capacity to disrupt the financial sector, impact national sovereignty, and affect established monetary transmission channels. Hence, it is no surprise that nation-states and tech-firms alike are now building new digital infrastructures that circumvent the legacy practices. Central banks, in particular, are racing to explore the issuance of Central Bank-issued Digital Currencies (CBDCs) in an attempt to rediscover the very essence and use of fiat cash.

In the past decade, the Bank of Canada (BoC) has emerged as an international thought leader on CBDCs. In early 2020, the BoC issued a contingency plan for the potential introduction of a CBDC and later that spring ran a global competition among universities to sample arm length’s designs. Being a finalist in this competition, this talk presents a design proposal for a Central Bank Digital Loonie (CBDL) based on careful academic research of the possible technological, legal, and economic components of such an unprecedented and historic expedition. We propose a two-phased approach. In the first phase, the BoC introduces a centralized platform as a public-good infrastructure that establishes digital cash and ensures global/domestic interoperability. In this phase, e-KYC-based authentication leverages existing private/public sector solutions but also safeguards users' privacy/data against third-party commercial interests while complying with AML/CFT. In the second phase, the BoC will expand the platform to an enterprise-level permissioned blockchain. This shared resource will transform CBDLs into "programmable e-money" within a “social operating system” that will enable Canadians to operate, innovate, compete, and thrive in this new global digital economy.

Glen Weyl


  Saturday, July 10, 11:00 - 11:40

Social Technology for a Political Economy of Increasing Returns     [Video]


Capitalist institutions are optimized for settings with decreasing returns (viz. value submodular in inputs). Yet the major technological engines of prosperity (e.g. cities, networks, etc.) all feature significant increasing returns (viz. supermodularity). Drawing on the theory of mechanism design, I will illustrate some simple approximately optimal institutions for addressing problems of increasing returns that are being deployed at significant scale and with some success today and highlight how radically different such institutions are than traditional capitalist or democratic formalisms. I will then argue that these nonetheless fall far short of optimizing for a world where increasing returns are pervasive, rather than occasional, causing significant challenges in practical applications, and sketch potential solution directions for this deeper problem. I will use this to illustrate an agenda of “social technology” that addresses other “known unknowns” in the optimality of social structures to allow them to perform better at impersonal scales much as e.g. AI attempts to imitate individual human intellect and signal processing/interface attempts to more completely satisfy human sensory systems.

Vassilis Zikas

Purdue University

  Saturday, July 10, 15:00 - 15:40

CryptoGT: Cryptography and Game Theory for the Analysis of Blockchains     [Video]


The combination of (distributed) cryptography and game theory has witnessed a flare-up of interest in the recent years, fueled in-part by the revolutionary blockchain and decentralized ledgers technologies. This talk will discuss models that enable the interplay of the two disciplines by addressing mismatches they have due to their independent development. We will discuss how these models can be employed to enrich the toolbox of security analysis of blockchains, and to facilitate the use of cryptographic tools in traditional economic analysis of games.