This type of study is called a quasi-experiment, and it allows scientists to estimate how much social media actually changes teens' mental health, or as Makarin says, "We can get causal estimates ...

This paper studies the effect of increased product market competition on executive compensation and incentives. We use a reform that simplified firm entry regulation in Portugal as a quasi-natural ...

Research on the persistence of institutions, using quasi-experimental techniques such as instrumental variables, has grown vastly more popular in recent years.