In Peru, opening payments to all players primarily benefited the largest institutions. Following the mandatory interoperability requirement of April 2023, adopting banks increased their deposits by approximately 9.6%, leading banks gained approximately 1 percentage point of market share, and deposit rates at adopting banks fell relative to those at non-adopting banks. The Peruvian case suggests that regulators must account for the initial competitive structure when designing interoperability rules.

The essentials

  • Interoperability can increase concentration when network effects and the initial market structure favor established players.
  • In Peru, after April 2023, banks adopting Yape or Plin increased their deposits by approximately 9.6% and reduced their deposit rates relative to non-adopting banks (Inter-American Development Bank, December 2025).
  • In Brazil, Pix followed an opposite trajectory: the Central Bank imposed portability rules and active monitoring, limiting the capture of gains by large institutions.
  • The challenge for Latin America is not the technical standard but the conditions surrounding it: who controls the data, who monitors concentration, who can switch banks without friction.

A common rule that consolidates the dominant player

The reasoning that led Peru to impose interoperability in 2023 was sound. Allowing all digital wallets to communicate with each other was supposed to break down silos, reduce transaction costs, and open the door to new entrants. This is the usual logic of open standards: a common infrastructure benefits all those who access it, small and large alike.

The result defied this intuition. According to an Inter-American Development Bank working paper published in December 2025, adopting banks increased their deposits by approximately 9.6% after mandatory availability by March 31, 2023 at the latest and gradual deployment from April to May 2023. Banks linked to the dominant digital wallet increased their deposit market share by nearly 10%. Deposit rates at adopting banks fell relative to those at non-adopting banks at precisely the moment when intensified competition was expected.

The mechanism is less mysterious than it appears. Interoperability enables payments between providers and instruments covered by each phase of the regulation, but it does not displace customer data or the trust relationship. Interoperability can disproportionately benefit the already-dominant player through network effects and its existing customer relationships, without establishing asymmetric access based on lack of data portability. The common standard expanded accessible networks while requiring Yape and Plin to open reciprocally to cross-platform transfers.

Lessons from Pix and UPI on the Rules of the Game

Brazil and India took different paths, and their trajectories illuminate what Peru did not do.

Pix, launched in November 2020 by the Central Bank of Brazil, became within two years the country’s most-used payment system, ahead of cards and cash. The Central Bank imposed portability rules for payment keys from the outset, allowing users to transfer their identifier from one institution to another without friction. It maintained active monitoring of pricing practices and concentration.

In India, the Unified Payments Interface, the instant payment system run by the National Payments Corporation, adopted a deliberately open architecture, without a dominant wallet backed by a bank in a dominant position. Mobile operators, fintechs, and banks coexist on the same infrastructure under symmetric access rules. Concentration remains a concern there, particularly around Google Pay and PhonePe.

These two cases do not prove that interoperability automatically opens markets. They show that outcomes depend notably on the initial market structure and the distribution of platform shares.

The Diagnostic Error Rodrik Would Have Made Without Peru

Dani Rodrik has long argued that common rules—commercial, financial, technical—produce shared prosperity only if they are conditioned on competition outcomes, not merely on technical criteria for access. His latest work, Shared Prosperity in a Fractured World, pushes this reasoning in the context of strained globalization: global standards often serve those who already have the capacity to mobilize them, and small players benefit only if the rules of the game are explicitly asymmetric in their favor.

The Peruvian case is a direct counterfactual. In local markets where Yape and Plin were already present, network effects associated with interoperability increased concentration according to the study. The common rule reproduced within Peru’s banking market exactly what Rodrik observes at the international level: formal liberalization that consolidates those already positioned to capture it.

The liberal market reading offers a useful competing interpretation. One can argue that concentration is a transitional phase, that the study links the relative decline in deposit rates to increased market power of adopting banks without demonstrating that efficiency gains are passed on elsewhere, and that regulators simply have not yet had time to correct initial distortions. Tyler Cowen or Philippe Aghion would insist that entry of new players into an interoperable market takes time, and that competitive effects play out over ten years, not eighteen months. This objection is legitimate. But the data studied show that network effects strengthened established banks after the mandate in two-platform markets.

The arbitrage between the two readings does not tip definitively toward one or the other. It depends on what the regulator does next. This is precisely what is at stake.

SME Financing: The Angle That Deposit Data Leaves in Shadow

The Peruvian figures concern deposits and banking market shares. They do not yet say what happens on the credit side for small businesses, which is the other central issue of financial inclusion in Latin America.

The link is nevertheless direct. A bank that consolidates its deposit base has increased resources for credit. The Inter-American Development Bank study notes a decline in microcredit volume in heavily exposed areas, whose interpretation remains uncertain. Higher banking concentration is associated with higher lending rates in some analyses, but the effect on SME credit costs depends on the country and other factors. The Inter-American Development Bank study on digital payments in Latin America, Beyond Cash, indicates that limited access to credit is a brake on digital payment adoption by businesses.

If Peruvian interoperability did strengthen the dominant player without opening financing, the effect on SMEs risks being the opposite of what standard promoters expected. Access to digital payment, which is improving, does not automatically translate into access to credit, especially when the bank capturing payment flows has no incentive to convert that information into a competitive credit offer.

Payment histories are the most valuable asset generated by a system like Pix or UPI: they allow one to assess the solvency of a merchant or artisan without formal credit history. Control of this data and the access conditions offered to competitors constitute a major issue for financial inclusion.

Latin American Regulators’ Agenda for 2035

Several Latin American countries are designing or expanding their own instant payment systems. Mexico launched CoDi then SPEI Mobile; Colombia, Argentina, and Chile are developing their own architectures. Each of these countries looks to Pix as a reference and to the Peruvian case as a warning.

The question that will open over the next ten years is as much architectural as regulatory. Two trajectories are emerging.

In the first, national systems remain closed infrastructures unto themselves, each with its own rules, its own dominant players, and its own concentration dynamics. Regional payment integration remains marginal, exporting SMEs continue to pay high exchange and transfer fees, and network effects consolidate country by country around large domestic institutions.

In the second, central banks build portability rules from the start, impose active monitoring of concentration, and condition access to payment data on obligations to share with accredited competitors. This trajectory could rest on regional cooperation among central banks to harmonize standards, along the lines of what the Bank for International Settlements has begun exploring with its mBridge project for cross-border payments.

The difference between the two trajectories does not hinge on technology. It hinges on three precise political decisions: whether data portability is mandatory from system opening or added afterward; whether the central bank actively monitors market shares within the system and can intervene; and whether access to payment histories is treated as shared infrastructure or proprietary asset.

The Peruvian case suggests that these decisions must be made before the interoperability requirement, rather than in response to its effects. A technical standard adopted without these safeguards takes years to correct, because the market positions it consolidates in turn create political and economic resistance to change. This is a lesson that development economists like Rodrik have posed for a long time regarding trade agreements: the rules of the game are negotiated before play, not during.

The signals to watch are concrete. The Brazilian regulator’s decision to cap market shares in Pix, or let them grow, will say much about central banks’ willingness to maintain competitive discipline in a mature system. The way Colombia and Mexico do or do not integrate portability into their future interoperability obligations will be a test of how widely the Peruvian lessons have spread. And the trajectory of SME financing in countries that have deployed instant payments for more than three years will allow measurement of whether payment inclusion translates, belatedly, into credit inclusion, or whether the gap remains structural.

These signals are readable before 2030. They should guide the trade-offs that Latin American regulators will make over the next two to three years, at the moment their systems move from launch to consolidation. It is in this window that architectures become fixed and network effects become difficult to redistribute.

Sources

  1. Inter-American Development Bank, When Interoperability Increases Market Power: Evidence from Peru’s Instant Payment Systems (2024)
  2. Inter-American Development Bank, Beyond Cash: The Digital Payments Revolution in Latin America and the Caribbean
  3. Dani Rodrik, Shared Prosperity in a Fractured World: A New Economics for the Middle Class, the Global Poor, and Our Climate, Princeton University Press