Since the COVID-19 pandemic began, several governments, including the U.S. federal government, have distributed cash payments to citizens in an attempt to alleviate the financial hardship caused by the global shutdown.
As the New York Times reports here, policymakers wonder if such payments are useful. Now we have data to help address that research question.
In offering most Americans two more rounds of stimulus checks in the past six months, totaling $2,000 a person, the federal government effectively conducted a huge experiment in safety net policy. Supporters said a quick, broad outpouring of cash would ease the economic hardships caused by the coronavirus pandemic. Skeptics called the policy wasteful and expensive.
[...]
A new analysis of Census Bureau surveys argues that the two latest rounds of aid significantly improved Americans’ ability to buy food and pay household bills and reduced anxiety and depression, with the largest benefits going to the poorest households and those with children. The analysis offers the fullest look at hardship reduction under the stimulus aid.
The full report is available here, and provides some excellent graphed examples of quasi-experimental data. We'll focus on Figure 1 from the report, reprinted above with permission from the authors.
The y-axis on the figure represents the percentage of Americans who "sometimes or often had not enough food to eat in the last seven days." The question is asked by U.S. Census' Household Pulse survey about once per month to a random sample of Americans. The dates of the two U.S. stimulus checks are indicated in the laddered, light-blue vertical lines. Payments occurred in December, 2020 and March, 2021.
Questions
a) The journalist writes that "the federal government effectively conducted a huge experiment in safety net policy". What is the independent variable in this "experiment?" What is the dependent variable (i.e., the one depicted in Figure 1)?
b) The independent variable here is not a true IV--it is a quasi-independent variable. What makes this variable quasi-independent?
c) The authors claim that the results from Figure 1 are consistent with the argument that the stimulus checks helped people. The authors wrote in their report: "Based on the speed with which we see hardship fall, we suspect much of this drop was the result of EIP checks, which the federal government was able to quickly deliver to bank accounts for most U.S. households following passage of both bills." Locate the areas on the figure that the authors are referring to.
d) This quasi-experimental study is probably best described as an interrupted time-series design. What is the "interruption" here? What is the time series?
e) A history threat is one potential internal validity problem in an interrupted time-series design. Explain what a history threat is and also why a history threat might be a problem here. What do you think--to what extent can we be sure it was the stimulus checks, and not some other pair of events, that is responsible for the increased food security depicted here?
You can see results for other variables in the report here, including figures that tracked people's feelings of anxiety and their feelings of depression.