Concerning outliers

Don’t believe the Newsweek poll showing Obama with a fifteen-point lead. But don’t believe the race is tied, either.

No, of course if the election were held today Barack Obama wouldn’t beat John McCain by fifteen points. A poll that shows a 55-36 partisan split may reflect a shift toward the Democrats, or it may reflect some sort of sample-selection bias; most likely it reflects some of each. And of course the election isn’t being held today.

Still, even outliers convey real information. Whatever the actual error is in polling (and it’s clearly much larger than the sampling error that gets reported as the plus-or-minus figure) it’s very unlikely that any competently done poll of a race that’s actually more or less tied yields a fifteen-point edge for one competitor. If the question is, “With Bush’s job performance ratings in the toilet, why is the Obama/McCain race still so close?” the answer may be “It isn’t.”

This is no time to be complacent. But it’s an excellent time to ignore the doomsayers. “Do not despair; one the thieves was saved. Do not presume; one of the thieves was damned.”

Author: Mark Kleiman

Professor of Public Policy at the NYU Marron Institute for Urban Management and editor of the Journal of Drug Policy Analysis. Teaches about the methods of policy analysis about drug abuse control and crime control policy, working out the implications of two principles: that swift and certain sanctions don't have to be severe to be effective, and that well-designed threats usually don't have to be carried out. Books: Drugs and Drug Policy: What Everyone Needs to Know (with Jonathan Caulkins and Angela Hawken) When Brute Force Fails: How to Have Less Crime and Less Punishment (Princeton, 2009; named one of the "books of the year" by The Economist Against Excess: Drug Policy for Results (Basic, 1993) Marijuana: Costs of Abuse, Costs of Control (Greenwood, 1989) UCLA Homepage Curriculum Vitae Contact: