RCT is also known as Field Trials. Economics is an inexact science of social behaviour. Each theory or study can be subject to biases, critiques and prejudices.

RCTS are conducted to measure comparative effects of a cause, that is a policy intervention randomly administered to a select group (treatment group) while keeping the behaviour or status of a compared group (control group) constant . It is a methodology of difference in differences — DID regression method. Other methods used in field experiments are propensity score matching and regression discontinuity design.

RCT findings in a certain region or for a certain population could not be extended to other regions or populations. There are contextual differences. Randomising the intervention raises ethical and social issues. Besides, RCTS are expensive. Correlation with other factors can affect the outcome. Treatment or intervention is independent — that is the assumption in RCT. It is called orthogonality condition. It must be satisfied, and not only assumed.