The returns came from access, not from boldness

Ebrahimian and Ljungqvist (Swedish House of Finance, February 2026) built patent-value measures for public and private firms from 1975 to 2015. Private firms' share of innovation value roughly doubled, from 16.5% to about 40%, tracking the top-1% wealth share from 23.2% to 35.8%. Their model attributes about two-thirds of the top-1% wealth-share increase to unequal access to private innovation.

That reframes the concentration argument entirely. The mechanism is not that wealthy people make braver bets — it is that the highest-return assets are structurally unavailable to public-market investors. Diversifying into public markets is not timidity; for most people it is the only door that opens. single source Working paper, not yet peer-reviewed, but methodologically serious.