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Glossary

equity premium

equity risk premium · ERP

The equity premium is the excess return investors demand for holding stocks over the risk-free rate, compensating for equity's higher volatility and correlation with bad states of the world. Historically it has averaged roughly 4–6% annualized, far larger than standard consumption-based models predict — the "equity premium puzzle."

How it works

The premium is the wedge between expected equity returns and a risk-free benchmark (typically short Treasuries or long real yields). Ex-ante it can be proxied by the earnings yield minus the real rate; ex-post it is realized excess return. When the risk-free rate is pulled toward zero, a stable required total return implies a mechanically wider equity premium.

Why it matters now

In the 2025–2026 regime of compressed real rates and AI-driven mega-cap concentration, debates over a "thin" forward equity premium — whether elevated multiples leave inadequate compensation for risk — sit at the centre of asset-allocation and melt-up narratives.

Example

If equities are expected to return 8% and the risk-free rate sits at 2%, the equity premium is 6%. A forecast that the risk-free rate is pulled toward zero while required total returns hold steady would widen that premium — a Maresca-style projection of expansion from 6% to over 20% reflects a regime where collapsing real rates, not rising equity returns, do the arithmetic.

Mechanism

ERP ≈ E[equity return] − risk-free rate

How desks use it

  • Sizing strategic equity allocation against a falling real-rate benchmark
  • Testing whether elevated multiples leave adequate compensation for risk
  • Comparing ex-ante earnings-yield premia across regions and regimes

Key moves

  • 1985Mehra and Prescott formalize the equity premium puzzle in the Journal of Monetary Economics.

Frequently asked

What is the equity premium?
The equity premium is the excess return investors require for holding stocks instead of a risk-free asset like short-dated Treasuries. It compensates for equity's volatility and its tendency to lose value precisely in bad economic states. Historical realized premia have averaged roughly 4–6% annualized in US data since the early 20th century.
Why is it called the equity premium puzzle?
The equity premium puzzle, named by Mehra and Prescott in 1985, is the finding that the historical premium is far too large to be explained by standard consumption-based asset-pricing models with plausible risk aversion. Matching a 6% premium required implausibly high risk-aversion coefficients, spawning decades of research into habits, rare disasters, and heterogeneous agents.
How does the equity premium relate to the risk-free rate?
The equity premium is defined relative to the risk-free rate, so a falling risk-free rate can widen the premium if required total equity returns stay fixed. When central-bank policy or financial repression pulls real rates toward zero, the same expected stock return implies a mechanically larger excess over the benchmark.
How is the equity premium estimated?
The equity premium is estimated either ex-post as realized average excess return, or ex-ante using forward proxies. A common ex-ante gauge is the equity earnings yield minus the real risk-free rate. Forward-looking estimates are noisier and regime-dependent, which is why allocators disagree sharply about whether today's premium is thin or adequate.

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By The Ledger DeskLast reviewed 2026-06-11