Doug Rivers of Stanford University and YouGov.com talks with EconTalk host Russ Roberts about the world of political polling. Rivers explains why publicly provided margins of error overstate the reliability of most polls and why it's getting harder and harder to do telephone polls. Rivers argues that internet panels are able to create a more representative sample. Along the way he discusses automated telephone polls, the Bradley effect, and convention bounce, and the use of exit polls in calling states in Presidential elections.