Method
To examine these questions empirically, a difference-in-difference regression analysis of data from
the General Social Survey (GSS) is employed to compare the change in job satisfaction of public
sector workers, relative to private sector workers, before and after September 11, 2001. Used in
econometrics in the context of natural experiments (Angrist & Pischke, 2009), a difference-indifferences
regression analysis estimates the before-after change in a treatment group (in this case,
government workers) relative to a control group (private sector workers) to gauge the net effect of
a treatment (in this case, the 9-11 attacks) on an outcome of interest (job satisfaction). In a regression
framework, the model is as follows: