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What is a randomised controlled trial?

Topics Covered:

  1. Population and associated issues, poverty and developmental issues, urbanization, their problems and their remedies.


What is a randomised controlled trial?


What to study?

For Prelims and mains: What is RTC? Why is it used, significance and criticisms.


Context: The new Economics Nobel laureates – Abhijit Banerjee, Esther Duflo and Michael Kremer – are considered to be instrumental in using randomised controlled trials to test the effectiveness of various policy interventions to alleviate poverty.


What is a randomised controlled trial?

It is an experiment that is designed to isolate the influence that a certain intervention or variable has on an outcome or event.


Why is randomised controlled trial so popular?

  1. At any point in time, there are multiple factors that work in tandem to influence various social events.
  2. RCTs allow economists and other social science researchers to isolate the individual impact that a certain factor alone has on the overall event.
  3. For instance, to measure the impact that hiring more teachers can have on children’s learning, researchers must control for the effect that other factors such as intelligence, nutrition, climate, economic and social status etc., which may also influence learning outcomes to various degrees, have on the final event.
  4. Randomised controlled trials promise to overcome this problem through the use of randomly picked samples.



Many development economists believe that RCTs can help governments to find, in a thoroughly scientific way, the most potent policy measures that could help end poverty rapidly. 


Criticisms of randomised controlled trials:

As per economist Angus Deaton, who won the economics Nobel Prize in 2015, “Understanding and misunderstanding randomised control trials” that simply choosing samples for an RCT experiment in a random manner does not really make these samples identical in their many characteristics. While two randomly chosen samples might turn out to be similar in some cases, he argued, there are greater chances that most samples are not really similar to each other.

Other economists argue that social science research, including research in the field of development economics, may be inherently unsuited for such controlled research since it may be humanly impossible to control for multiple factors that may influence social events.


Sources: the Hindu.