Equally important to the concept being measured is the explanatory mechanism in social science research. In “Nuts and Bolts for the Social Sciences,” Jon Elster, describes the role of casual mechanisms in a strong theory. The casual mechanism is critical for social science research because it provides an explanation for why two variables are correlated. Correlation without an explanation as to why these two variables may be connected provides a very weak causal explanation and provides little to no value to the discipline. There is the commonly cited example of the correlation between ice cream consumption and murder rates. Stating that as ice cream consumption increases so does the murder rate. There is no causal argument between the two, however, and they are both most likely caused by a third variable such as higher temperatures.

The difficulties in trying to prove causality are demonstrated in Donald Campbell and Laurence Ross’s study, “The Connecticut Crackdown on Speeding: Time series Data in Quasi-Experimental Analysis” In the late 1950s the government to reduce traffic fatalities introduced harsh penalties for speeders. When examined at a single data point, the difference between 1955 and 1956 it appears that there was a significant decline in the number of traffic fatalities in the state. Also in comparison to the average of the other New England states it appears that there was a significant decline in fatalities after the implementation of the traffic laws. When compared to each northeastern state individually, however, Rhode Island experienced an even sharper drop in traffic fatalities, without the introduction of strict traffic laws. As argued by Campbell and Ross, this comes together for an overall inconclusive study on the effect of the speeding laws far from the certainty with which the governor declared the laws a major success. The inconclusive nature of the statistical analysis requires, if a relationship is to be determined, a reexamination of the casual mechanism as part of an overall improved theory