There are many good reasons why this is the case. Jobs often require good writing skills for career success; writing is also clearly an important part of communication in daily life; and excellent writing skills are needed for attaining excellent results in essay examinations.
For instance, when an economics student writes about expansionary fiscal policy and the details of how it works or functions, that is great - but what is the impact or implication of the policy? What is the importance of this particular policy? If the argument goes on to say that expansionary fiscal policy can reduce demand-deficient unemployment in theory, then the argument has a real impact and importance, and tells the reader the full implication of the theory.
Studying hard for economics will provide you with a strong theoretical background to answer essay questions accurately and properly, detailing the importance and implications of your arguments.
Thank you for reading this article, and cheers.