Discussion paper

DP16335 Do the Effects of Individual Behavioral Biases Cancel Out?

A major criticism of behavioral economics is that it has not shown that the idiosyncratic biases of individual investors lead to aggregate effects. We construct a model of a general-equilibrium production economy with a large number of firms and investors. Investors' beliefs about stock returns are determined endogenously based on their psychological distances from firms; consequently, investors are optimistic about some stocks and pessimistic about others. We consider two examples: one where portfolio errors cancel out and the other in which the behavioral biases cancel out when aggregated across investors. We show asset prices and macroeconomic aggregates are still distorted.


Uppal, R and H Bhamra (2021), ‘DP16335 Do the Effects of Individual Behavioral Biases Cancel Out?‘, CEPR Discussion Paper No. 16335. CEPR Press, Paris & London. https://cepr.org/publications/dp16335