Minneapolis Fed: Falling Labor Share and Low Investment Support High U.S. Stock Valuations

A new research paper from the Minneapolis Federal Reserve explains why U.S. stock market valuations have remained elevated above historical norms for the past 25 to 30 years, despite concerns from investors about overpricing. Economists Jonathan Heathcote, Andrew Atkeson, and Fabrizio Perri argue that a decline in labor's share of corporate output—coupled with weak corporate investment—has mechanically driven up valuation ratios relative to earnings, even without changes in expected returns or growth rates.^[1][2]

Traditionally, metrics like price-to-earnings ratios have signaled that stocks look expensive compared to dividends, earnings, output, or replacement costs of capital.^[2] However, the researchers highlight that valuations appear more reasonable when measured against free cash flow, as companies have faced less pressure to invest heavily in new capital.^[1] This shift means more equity value flows to shareholders rather than reinvestment, sustaining higher stock prices amid growing corporate earnings.^[1]

At the core of this trend is rising economic inequality, particularly the falling share of profits going to workers versus capital owners. As labor's portion of corporate output has declined, a larger slice benefits investors, propping up market valuations and contributing to the prolonged stock boom.^[1][2] According to Bloomberg's coverage of the paper, this dynamic has kept stocks high beyond simple explanations like investor optimism or "animal spirits."^[1]

This research challenges the narrative that stocks are irrationally priced and destined to revert to historical means. Instead, it points to structural macroeconomic forces—like subdued investment and shifting profit distribution—as key drivers.^[2] Investors and policymakers alike have debated these high valuations for years, with tools like the Fed Model comparing stock earnings yields to Treasury yields often flashing cautionary signals.^[3]

The implications extend to everyday Americans and the broader economy. Wealthier households, who hold most stocks, have benefited disproportionately from these gains, exacerbating inequality while workers see less from corporate profits.^[1] For markets, this means sustained high valuations could persist unless trends reverse, such as through rising corporate investment.

Recent developments add nuance. Tech giants are now ramping up massive capital spending on AI infrastructure, potentially eroding free cash flows and pressuring valuations if labor's share doesn't rebound.^[1] The Federal Reserve monitors these risks closely, noting that high asset prices reflect low risk premiums and elevated investor appetite, though measures like equity risk premiums remain hard to pinpoint precisely.^[5]

Looking ahead, the paper's authors discussed in a Bloomberg Odd Lots podcast the possibility of a reversal if investment picks up or profit shares shift.^[1] While corporate earnings growth remains a straightforward stock driver, watching labor share trends and capex will be crucial for gauging whether the bull market's macro foundation holds.^[1][2] This analysis offers investors a framework to assess if current highs are justified or vulnerable to change.