Answer: The main reason why some people don’t accept a social science discipline like economics or psychology as a true science is the fact that human behavior is deemed too capricious to be measured and quantified. For example, any object that is thrown upward will fall back down hence the law of gravity. But if we give someone $100, what the person will do with the money is infinitely variable. He could save it all, save most of it, spend it all, spend most of it, donate it to charity, or even give it back to us. The endless possibilities are the key reason why social science is perceived as an inexact science and in some cases, not a science at all.
Simon Nguyen, M.A. Economics