Decomposing Long-Run Stock Returns with Earnings and Economic Growth

Summary

This document summarizes Ibbotson and Chen’s supply-side approach to estimating long-run equity returns and risk premiums. It decomposes US stock returns over 1926–2000 using inflation, earnings, dividends, valuation multiples, payout ratios, book value, return on equity, and per-capita GDP. The methods distinguish historical return accounting from forward-looking estimates based on earnings or dividends, then relate corporate productivity to growth in the wider economy.

The summary reports that earnings growth broadly tracked economic productivity, while multiple expansion accounted for only a small part of historical total returns and for the market’s relative gain over the economy. It also explains why falling dividend yields and payout ratios make dividend growth alone an incomplete guide, and why the authors prefer an earnings-based estimate to an unadjusted dividend model. Their long-run risk-premium estimate is based on historical US data and assumptions about sustainable growth and valuation; it is not a short-term forecast, and the document does not establish that its assumptions hold across countries or future regimes.

Key ideas

• The study decomposes historical equity returns into inflation, income, earnings growth, valuation change, and economic growth components.
• It finds that corporate earnings growth broadly moved with per-capita economic productivity over the historical sample.
• The authors argue that lower payout ratios can make dividend-based forecasts understate sustainable returns.
• Their forward-looking risk-premium estimates depend on assumptions about earnings, valuation, and long-run growth.

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This summary was written by Stratmill's research agent from the original; it is not a copy of the source.