Os efeitos do open finance na concentração de crédito no Brasil (2017–2025): uma análise empírica com dados em painel e séries temporais

Abstract

The high level of concentration in the Brazilian credit market represents a longstanding structural characteristic of the national financial system, with significant implications for competition, credit costs, and financial inclusion. In this context, the Central Bank of Brazil implemented Open Finance in 2021, a public policy based on the standardized sharing of financial data through consumer consent, aimed at reducing information asymmetries and enhancing market contestability. Accordingly, this study investigates the effects of Open Finance on credit market concentration in Brazil, considering the period from 2017 to 2025, with the years prior to 2021 serving as a baseline to capture market dynamics before the policy implementation. The research adopted a quantitative approach, using econometric models with panel data and aggregated time series, estimated using the Ordinary Least Squares (OLS) method. Specifically, three hypotheses are tested: (H₁) the implementation of Open Finance is associated with a reduction in the market share of the five largest banks; (H₂) Open Finance is associated with a reduction in the average banking spread; and (H₃) the growth in the number of active fintech firms is associated with a reduction in credit market concentration. For H₁, concentration is examined through institutions’ relative market shares, with particular emphasis on the differential effect on the group of the five largest banks (RC5) in the post–Open Finance period. For the remaining hypotheses, aggregated measures of the financial system are employed, including the combined market share of the RC5 group and the average banking spread. The results suggest that the implementation of Open Finance was associated with a reduction in the market share of the five largest banks and with a decrease in the average banking spread. On the other hand, no statistically robust evidence was found that the growth in the number of active fintech firms, considered in isolation, contributed to a reduction in credit market concentration over the analyzed period. Overall, the findings indicate that Open Finance may be related to changes in the structure of the Brazilian credit market, particularly with respect to the relative decline in the participation of large institutions and the compression of intermediation margins. Nevertheless, the activity of fintech firms alone does not appear to have been sufficient to produce significant changes in aggregate market concentration within the time horizon considered.