economics Paradigm Challenge

The stock market is way more predictable than the textbooks say, as long as you ignore those 'permanent' growth trends.

March 24, 2026

Original Paper

Expected Returns with Trends and Cycles

Sebastian Hillenbrand, Odhrain McCarthy

SSRN · 6332619

The Takeaway

The famous 'random walk' theory suggests markets are hard to predict. This paper argues that the standard metric (price-dividend ratio) is just 'noisy'; when you filter out long-term trends in cash flow, the market's return becomes highly predictable, explaining 22% of the variance over a five-year horizon.

From the abstract

We argue that cash flow growth contains a permanent trend component, rendering the price-dividend ratio a noisy proxy for expected returns. Jointly filtering trend growth, cash flow cycles, and expected returns via an Extended Kalman Filter, we show this cash flow noise generates severe attenuation bias in standard predictive regressions. Purging cash-flow trends and cycles restores return predictability, delivering out-of-sample R 2 of 9% at one-year and 22% at five-year horizons, where traditi