In the literature the common view is a trade-off between internal and external validities, and natural experiments
lie in the middle of the scale (16).
I leave the last word to Acemoglu and co-workers in Chapter 7 of Natural Experiments
There were 7 randomized controlled trials, controlled clinical trials, or natural experiments
with a treatment/no treatment comparison.
The standard approach to identifying the elasticity has been to use natural experiments
generated by changes in the progressivity of the income tax.
Despite the strong relationships revealed by the observational studies and natural experiments
, results from nonmanipulative studies were equivocal.
They are generated by well-designed analyses, but even the best natural experiment
does not have the power of a controlled laboratory experiment, so we (and the authors) must apply some prior judgment.
Recently, however, two studies, each utilizing data on a treatment and control group of temporarily impaired workers, have employed natural experiments
to examine the impact on the duration of work absence of an increase in benefits.
Component A: To support a 5-year multi-center research network of innovative, non-health system-based, natural experiments
approaches to alter the diabetogenic characteristics of US communities.
Just as medicine increasingly has relied on clinical trials rather than observational studies to understand the effects of drugs, diet, and behavior on human health, economists have increasingly published the results of natural experiments
in which people are exposed to pollutants in a manner that is plausibly random and health effects are observed.
The evaluation explores the impact of FDK as compared to half-day kindergarten (HDK) by utilizing data from natural experiments
occurring in districts across the state.
The Sun makes fantastic natural experiments
that allow us to test our ideas about its effects on the climate," lead author of a report newly published in Geophysical Research Letters Prof.
It begins with a description of the differences between formal experiments and natural experiments