Develops a four-layer functional model of payment systems (money, settlement, payment schemes and user applications), argues that only settlement has the natural-monopoly features of genuine public infrastructure, and maps the design choices through which a publicly operated scheme can affect competition. Applies the framework under domestic proportionality review to Brazil's Pix, the US FedNow Service and the proposed digital euro, against regulatory alternatives such as mandated common standards and interoperability requirements.
Research
Central banks increasingly operate retail payment systems themselves, from Brazil's Pix and the US FedNow Service to the proposed digital euro. Jeff's research asks which functions within these systems genuinely require exclusive public provision and which should be left open to competition, and what follows under domestic public law and international trade law.
The research develops a functional framework that separates money, settlement infrastructure, payment schemes and user applications. It maps the design choices that can affect competition at the scheme layer, and evaluates them under the principle of proportionality and under the World Trade Organization's General Agreement on Trade in Services (GATS). The same method is then carried from domestic systems to cross-border arrangements, in four connected papers.
Research program: public payment systems between proportionality and international trade law
Carries the framework into the General Agreement on Trade in Services: which payment-system functions fall within the Agreement's scope, which disciplines the design choices engage, and how the necessity test changes the analysis by placing the burden of justification on the state.
Asks whether linking fast payment systems across borders is a form of regulatory treatment that must be extended to all WTO Members, and how multilateral platforms such as Project Nexus fare under that discipline.
Tests whether the framework holds when several central banks pool monetary functions on a shared platform, with mBridge as the core case, including questions of attribution and the security exception.
Other work in progress
Asks whether the GATS should discipline a central bank's operation of a retail payment scheme as such, or only design choices that foreclose the scheme layer to competition: exclusivity, mandatory participation, or pricing competitors cannot match. Applies the argument to the digital euro, Pix and FedNow, from treaty coverage, where the Article I:3 exclusion appears to reward foreclosure, to necessity, where a deferential domestic proportionality finding becomes a defense the operator must discharge. Proposal submitted to the SIEL 2027 Global Conference.
Compares stablecoin legislation in eight jurisdictions by how each attaches its new regime to existing legal categories, not by what it requires. Shows that a regime fastened to a category from which another provision has removed the paradigm case binds only the residue, the instruments it was written to exclude, and identifies the drafting requirement that avoids this: definitional conformity.
Tools
An interactive simulator that places a stablecoin issuer's balance sheet on the money-ness spectrum using Basel liquidity parameters, and tests it against the stablecoin regimes of the EU, the United States, the United Kingdom, Hong Kong and Singapore, with Brazil as a comparator.