Radar Perene / Archive / science

Bank spread: what Brazilian research has already measured

◦ Index methodology v2.2 (working papers with DOI). See the methodology.

Science

At the same counter, on the same day, the same bank practices two numbers that seem to belong to different countries: what it pays those who leave money deposited and what it charges those who need to borrow it. The distance between the two has a name, a quarter-century of literature, and one trait that international comparisons register with uncomfortable constancy: in Brazil, it ranks among the widest in the world. What almost never migrates from the literature to the news is the most interesting part — the decomposition of where that distance comes from.

The bank spread is the difference between a bank's funding cost — what it pays to obtain resources — and the rate it charges on credit operations. It is not a synonym for profit: inside the spread live expected default, administrative costs, taxes, reserve requirements and, only then, the margin. Measuring the size of each slice has been an active Brazilian research program since the 1990s.

The question "why does credit cost so much in Brazil?" is usually answered with a single culprit, chosen according to the mood of the debate. The literature answers differently: with an itemized bill, published and updated as open data.

An itemized bill

The systematic measurement effort officially began in 1999, when the Central Bank launched the project Juros e Spread Bancário no Brasil — an annual diagnostic agenda that evolved into today's Banking Economics Report (Relatório de Economia Bancária), published every year with the decomposition of the cost of credit. The data infrastructure is open: the series of average rates, spreads by credit line and default are in the SGS, the same series system the house described in open data from the Central Bank, and the technical studies appear in the monetary authority's public working paper series.

The decomposition that emerges from those editions, described in qualitative terms, is stable in its main feature: the fattest slice of Brazil's cost of credit is, recurrently, the cost of default — the price that borrowers who pay carry for those who do not. Around it orbit the administrative costs of the operation, the tax wedge and reserve requirements, and the institutions' financial margin. The exact proportions vary by edition and by credit line — which is why this text describes them without pinning percentages: the reader checks the current decomposition in the year's report, at the source.

What the literature discusses beyond the bill

The decomposition organizes the debate; it does not close it. Three fronts of the Brazilian literature deserve the record. The first is banking concentration: studies investigate how much of the margin is explained by market structure — few large banks — with results that vary by period and method; the relation exists in the data, its magnitude remains in dispute. The second is collateral recovery: research associates part of the expensive default with the historical slowness of recovering overdue credit, and institutional reforms of that machinery were followed by the literature as quasi-experiments. The third is the recent frontier: what the entry of new digital competitors and the instant-payments infrastructure changes — or does not — in margins; the answer is still being measured, and writing a definitive conclusion today would be trading research for cheering.

Note what the sum of these fronts says about method: a phenomenon with a decade and a half of headlines and a new culprit every season has, in the literature, an anatomy of multiple measured causes — none of them sufficient alone. That is the pattern that separates diagnosis from slogan.

When credit turns into fear, the archive records it

There is a point where the theme touches the house archive: the price of credit does not live only in contracts — it also appears on the stock exchange, in the discount bank shares register when the quality of their loan books comes into doubt. In March 2020, the monitoring recorded the Finance/IBOV ratio sinking to the mark the archive associates with credit scares — the episode is documented in the mark of credit fear. In numbers: that same month, the Selic was cut to 3.75% per year — and wholesale money getting cheaper while the banking sector was discarded with conviction is the cleanest illustration the archive offers that the base rate and the price of credit risk are distinct variables, capable of moving in opposite directions in the same session.

The distinction closes the circle with the definition at the top: whoever confuses spread with "high interest" expects it to fall when the Selic falls. The historical series — open, verifiable — shows a much looser coupling, because the largest slice of the bill is not the cost of money; it is the cost of those who do not pay.

Frequently asked questions

Is the bank spread the bank's profit?

No. The margin is one of the slices — alongside default, administrative costs, taxes and reserve requirements. The annual decomposition in the Banking Economics Report exists precisely to separate those layers.

Does a low Selic mean a low spread?

The relation is weak and documented as such. The Selic moves the funding cost; the spread is dominated by components that do not depend on it — default first among them. The 2020 episode, with the base rate at a historic low and credit still expensive, is the classic counterexample.

Are international comparisons fair?

Partially. Differences in methodology, loan-book composition and taxation distort the ranking — and the Brazilian literature itself discusses those caveats. Once adjusted, Brazil remains in the upper positions; the caveat changes the step, not the floor of the building.

Where can the primary data be checked?

In the rate, spread and default series of the Central Bank's SGS and in the editions of the Banking Economics Report — all open, no registration, citable by series code.

The economics-as-science trail ends here — and the next one begins where every measurement can slip: two series that "move together" with no relation at all. Spurious regression →

House readings: each day's cost of money is in today's note, in the Daily; the credit scares the stock market has already recorded, in the precedents, in the Atlas.

Applying this literature to a specific credit segment is the kind of deeper work the house conducts on request.

Characters: Rates (Selic)