Household Portfolio Underdiversification and Probability Weighting: Evidence from the Field
We explore the relation between probability weighting and household portfolio underdiversification in a representative household survey, using custom-designed incentivized lotteries. On average, people display Inverse-S shaped probability weighting, overweighting the small probabilities of tail events. As theory predicts, our Inverse-S measure is positively associated with portfolio underdiversification, which results in significant Sharpe ratio losses. We match respondents’ individual stock holdings to CRSP data and find that people with higher Inverse-S tend to pick stocks with positive skewness and hold positively-skewed equity portfolios. We show that these choices reflect preferences rather than probability unsophistication or limited financial knowledge.
Non-Technical Summaries
- Many investors choose to hold stocks in individual firms, hoping to pick the 'the next Apple,' despite knowing that such investments...
Published Versions
Stephen G Dimmock & Roy Kouwenberg & Olivia S Mitchell & Kim Peijnenburg, 2021. "Household Portfolio Underdiversification and Probability Weighting: Evidence from the Field," Review of Financial Studies, Society for Financial Studies, vol. 34(9), pages 4524-4563. citation courtesy of