The previous data about the death penalty are hypothetical, not based on any real study. However, here are some real data from the FBI's Uniform Crime Report for 2001:

U.S. REGION	MURDER RATE IN 2001 (PER 100,000 PEOPLE)
Northeast	4.2
Midwest	5.3
West	5.5
South	6.7
National average	5.6

There were 0 executions in the Northeast in 2001. In contrast, almost 80% of all of the executions in the United States in 2001 were in the South.

If we use the South as our "death penalty region" and the Northeast as our "no death penalty control group," we could make the claim that the 2001 murder rate is actually significantly higher in Death Penalty states than in non-death-penalty states.

What type of quasi-experimental design would this situation approximate?

nonequivalent control group, posttest only

nonequivalent control group, pretest-posttest

Think critically for a moment. What is missing from this data? What kinds of information would you like to see before you agreed that the death penalty actually increases murder?