How Banks Create Gridlock in Payment Systems to Save Liquidity: The Case of Canada
What this paper finds — and why it matters
This paper uses detailed transaction-level data from Canada’s new high-value payment system (HVPS) to show how participants save liquidity by strategically exploiting the gridlock resolution arrangement built into the system. Observed behaviors are found to be consistent with the equilibrium of a “gridlock game” that captures the key incentives participants face: by withholding outgoing payments to induce gridlock events, participants trigger the system’s bilateral netting algorithm, which settles stuck payment queues at lower liquidity cost than bilateral sequential settlement would require. The findings have implications for the design of high-value payment systems and shed light on financial institutions’ liquidity preference in payment system environments.
Summary based on a working paper version, AI-assisted and human-reviewed. See the linked published article for the authoritative version.
Q1. What is the gridlock resolution arrangement and why do banks exploit it?
Modern high-value payment systems (HVPSs) include a gridlock resolution mechanism that activates when a set of payments are mutually stuck in queues—each waiting for an incoming payment before it can be sent—and resolves them simultaneously via bilateral netting, which requires less settlement liquidity than sequential settlement; banks strategically withhold outgoing payments to trigger these events and thereby save liquidity. The HVPS studied is Canada’s new large-value transfer system, which replaced the older LVTS. The gridlock game captures the incentive structure: if a bank expects counterparties to send payments that would be netted against its own obligations in a gridlock, it is optimal to withhold and wait rather than settle bilaterally at higher liquidity cost.
Q2. How is the gridlock game formalized?
The “gridlock game” is a formal game-theoretic model that captures the key incentives participants face in the HVPS: players choose whether and when to send payments, and the equilibrium characterizes the strategic withholding behavior as a rational response to the liquidity-saving opportunities created by the gridlock resolution mechanism. The equilibrium of this game is shown to be consistent with the actual patterns observed in the HVPS data: the timing, magnitude, and counterparty structure of strategic withholding are aligned with the game’s equilibrium predictions.
Q3. What are the implications for HVPS design?
The finding that participants strategically exploit the gridlock resolution mechanism has implications for HVPS design: while gridlock resolution was intended as an exception-handling mechanism for unintended payment queue build-ups, participants have adapted to use it as a routine liquidity management tool, changing the system’s effective operation in ways the designers may not have anticipated. System designers must account for the strategic response of sophisticated participants when evaluating the performance of gridlock resolution mechanisms, since the equilibrium behavior changes the frequency, timing, and magnitude of gridlock events relative to the non-strategic benchmark.
Q4. What does the evidence reveal about banks’ liquidity preferences?
The strategic gridlock behavior reveals that financial institutions place significant value on conserving payment system liquidity—enough to coordinate timing of payment submissions in ways that exploit system-level netting opportunities—consistent with liquidity being a scarce and valuable resource in modern payment systems. This preference for liquidity conservation is amplified in environments where central bank reserves are costly and where payment system participants face collateral or reserve constraints.
Key concepts
gridlock in high-value payment systems : a situation in which a set of payments are mutually stuck in queues—each waiting for incoming funds before outgoing payment can be made—requiring the system’s bilateral netting algorithm to simultaneously settle them; exploited strategically by banks to save settlement liquidity. gridlock game : the paper’s game-theoretic model of strategic payment submission timing in an HVPS; captures the incentive to withhold outgoing payments to trigger gridlock resolution events that settle payment queues at lower net liquidity cost. bilateral netting in HVPS : the gridlock resolution mechanism that settles multiple mutually stuck payments by computing net obligations among participants and settling only the differences; requires less total settlement liquidity than sequential bilateral settlement and is the mechanism banks exploit in the gridlock game.