A Cold Shower for the Hot Hand Fallacy
(Incomplete Draft, Please do not circulate or post online)
Joshua Millera and Adam Sanjurjob
∗†‡§
December 26, 2013
Abstract
In their seminal 1985 paper, Gilovich, Vallone and Tversky (GVT) show that the hot hand
belief commonly held by basketball players, coaches and observers is a fallacy. This was an
important result for the early behavioral economics program because it was one of the first
examples of experts systematically committing a cognitive fallacy under high stakes in their
domain of expertise. The original results have been subsequently reinforced by the combination
of repeated failures to detect a hot hand effect and the continued insistence of its validity by
professionals and lay persons alike. The hot hand fallacy has become an exhibit of the power of
cognitive illusions more generally; not only are they economically meaningful, but they can be
robust to learning and advice.
We demonstrate that the hot hand belief is not a fallacy. The conclusion of the original
GVT study relies principally on a controlled shooting experiment because of confounds present
in game data. We design a shooting task and develop statistical measures that together have
superior identifying power. We find overwhelming evidence of the hot hand both in our study
and in earlier controlled shooting studies, including GVT. Additionally, in a betting task using
videos of our shooters, we find that participants can detect streakiness, performing significantly
different than chance levels.
JEL Classification Numbers: C12; C14; C91; C93; D03.
Keywords: Hot Hand; Experimental Economics; Behavioral Biases.
∗
a: Department of Decision Sciences and IGIER, Bocconi University, b: Fundamentos del Análisis Económico, Universidad
de Alicante.
†
Both authors contributed equally, and alternate order of surnames across joint papers.
We thank José Valeiro, president of the Pabellón Municipal de Betanzos, for generously providing us with many
hours of exclusive gym access in order to prepare and conduct our experiments, Javier Lopez for his jack-of-alltrades assistance in organizing and conducting experimental sessions, and Cristina Lopez for greatly improving the
translation of our experiment’s instructions to Spanish. Financial support from the Department of Decision Sciences
at Bocconi University, the Spanish Ministerio de Ciencia y Tecnologı́a and Feder Funds (SEJ-2007-62656), and the
Spanish Ministry of Economics and Competition (ECO2012-34928) is gratefully acknowledged.
§
We thank Thomas Gilovich twice: first for locating the records of his data and scanning them for us and second
for making us aware of the work of Jagacinski, Newell, and Isaac (1979). We thank Richard Jagacinski for locating
his computer punch card data and having them converted to electronic format for us.
‡
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