Home bias in officiating: Evidence from international cricket

We use data on leg before wicket decisions from 1000 test cricket matches to quantify the systematic bias by officials (umpires) to favour home teams. We exploit recent changes in the regulation of test cricket as a series of natural experiments to help to identify whether social pressure from crowds has a causal effect on home bias. Using negative binomial regressions, we find that home umpires favour home teams and that this effect is more pronounced in the later stages of matches.