We consider a prediction market in which traders have heterogeneous prior beliefs in probabilities. In the two-state case, we derive necessary and sufficient conditions so that the prediction market is accurate in the sense that the equilibrium state price equals the mean probabilities of...

The paper investigates the minimum level of individual rationality that is needed for market prices to converge toward their equilibrium level. It does so by examining the theoretical and methodological foundations of the 'zero-intelligence' (ZI) agent trading approach, with which Gode and...

In sports betting markets, bets on favorites tend to have a higher expected value than bets on longshots. This article uses a data set of almost 45,000 professional single tennis matches to show that the favorite-longshot bias is much stronger in matches between lower-ranked players, in...

How do decision makers weight private and official information sources which are correlated and differ in accuracy and bias? This paper studies how traders update subjective risk perceptions after receiving expert opinions, using a unique data set from a prediction market, the Hurricane Futures...

This paper studies the impact of belief elicitation on informational efficiency and individual behavior in experimental parimutuel betting markets. In one treatment, groups of eight participants, who possess a private signal about the eventual outcome, play a sequential betting game. The second...

Racing data provides a rich source of analysis for quantitative researchers to study multi-entry competitions. This paper first explores statistical modeling to investigate the favorite-longshot betting bias using world-wide horse race data. The result shows that the bias phenomenon is not...

According to the favorite-longshot bias, longshots are overbet relative to favorites. We propose an explanation for this bias (and its reverse) based on an equilibrium model of informed betting in parimutuel markets. The bias arises because bettors take positions without knowing the positions...

In parimutuel betting markets, it has been observed that proportionally too many bets are placed on longshots, late bets are more informative than early bets, and a sizeable fraction of bets are placed early. We propose an explanation for these facts based on equilibrium incentives of privately...

A well-documented anomaly in racetrack betting is that the expected return per dollar bet on a horse increases with the probability of the horse winning. This socalled "favorite- longshot bias" is at odds with the presumptions of market efficiency. We offer a new solution to this much-debated...