First, they assume that all 20 countries are hit by common but unobservable shocks.

ECONOMIST: A shocking error

One cannot draw such conclusions from such studies if they do not control for the unobservable factors that drive Medicaid enrollment.

FORBES: Why Medicaid is a Humanitarian Catastrophe

In doing so, we would be ignoring risks that are unobservable and which we routinely ignore (and properly so) in other circumstances.

WSJ: The Panic Over Fukushima

Banco Santander (nyse: STD - news - people ) give to one other when seeking extra funding, and it is based on unobservable rates.

FORBES: Market Scan

Residents of Fukushima who are concerned that residual radiation will cause additional risk can avoid that by leaving, but they need to recognize that any additional cancers will be statistically unobservable, hidden well below those of natural cancer and the other dangers of modern life.

WSJ: The Panic Over Fukushima