This is a living document of natural experiments and associated research questions that one might be able to study with them. It is most recently updated on 01/05/2022.

Removal of Dislike Counts on YouTube

What happened: On Nov 10, 2021, YouTube removed the dislike counts videos. While the likes count will be public to viewers, the dislikes count will only be privately accessible to the content creator. The change was rolled out on YouTube during that day, creating a sharp policy change. Notably, the dislike button was not removed, i.e., viewers can still click dislike, but they cannot see the total number of dislikes of a video.

What questions can be studied:

  1. How does the removal of an engagement feature affect viewers’ engagement towards videos?
  2. How does the (asymmetric) removal of negative quality signal affect content quality on the platform?
  3. …

Congress Cut Finance to Superconducting Supercollider

What happened: On Oct 19, 1993, U.S. congress voted to cancel the financing for superconducting supercollider. By then, the project was being constructed in Texas. The cancellation resulted in a significant shock to the physics job market, as graduates were not able to find academic jobs. Many of them, with solid quantitative training, instead found jobs in the finance industry, thereby creating a sudden influx of high-quality talent to the industry.

What questions can be studied:

  1. How does the (arguably exogenous) influx of high-quality talent affect the finance industry?
  2. …