Introduction
The term ‘randomised controlled trial’ (RCT) came to be used in the economic parlance due to the works of Economics Nobel laureates—Abhijit Banerjee, Esther Duflo (Massachusetts Institute of Technology), and Michael Kremer (Harvard University), who were awarded 2019 Nobel Prize in Economics for their innovative work in applying experimental approaches to tackle global poverty.
RCTs are mainly used as standard tools in medical field to evaluate the efficacy of a drug. In this approach, volunteers are randomly allocated to groups; for instance, there can be two groups—one group is administered the drug being evaluated, while another is treated with a placebo, i.e., not a real medicine but a substance with no medicinal effect, given just for psychological effect.
Understanding Randomised Control Trial
A randomised control trial is an experiment which aims to ascertain that a certain variable or intervention does not influence an outcome. For this, the experiment is so designed that it isolates any such influence that may affect the outcome. As per the Prize Committee, RCT is a new approach to obtaining reliable answers about the best ways to fight global poverty.
RCT began to be used in the field of economics in the 1990s by Mr Banerjee, Mr Duflo, and Mr Kremer. It was used in Kenyan School to analyse the effect of free meals and books on learning. Later on, this approach was also used in India, where it was popularised through their book, viz., Poor Economics, published in 2011.
How RCT Works?
RCTs are considered an effective tool for research as they isolate the individual influence that a certain factor alone is capable of casting on the overall event. If a social science researcher seeks to evaluate the effect of employing more teachers on children’s learning ability, then the effect of other factors like intelligence, nutrition, climate, economic and social status, etc. must be controlled so as to arrive at the conclusion. These various factors can have varying degree of influence on the final result. This problem is overcome in RCT through randomly picked samples. Researchers using RCTs are of the view that all random samples relate to the same set of ‘confounding factors’; so they are similar to one another. When a researcher uses these random samples, they conduct study by varying appropriate variables to find out the effect of these individual variables on the final outcome.
According to many development economists, RCTs can be a tool to find the most effectual policy measure to solve the problem of poverty through a thoroughly scientific way.
Criticism
Nobel prize laureate Angus Deaton (awarded in 2015) criticises RTC approach in a paper, titled ‘understanding the misunderstanding randomised control trials’. He is of the view that merely choosing samples for an RCT experiment does not make them identical in their characteristics. There are always chances that most samples are not identical to each other. Others are of the view that the RCT approach is more suitable for physical sciences rather than social sciences. They argue that social science research may be inherently unsuited for such controlled research. Humanly, it seems impossible to control multiple factors, which may have impact on social events.