How did the influential economist John Maynard Keynes explain his remark that though economics is an easy subject compared with the higher branches of philosophy or pure science, it is a subject at which few excel?

B) Good economists must possess a rare combination of gifts.

Explanation:

Economics is a social science that focuses on studying scarcity. Since all resources are scarce, economics tries to determine how to allocate resources more efficiently in order to produce the most possible benefits. We are all economists whether we like it or not. When we spend our money (scarce resource) we try to get the largest benefit out of it, the same applies to our time. We decide to study for a test and get a good grade, or simply take a very long nap.

The problem with economics and all social science, is that they are not exact. There is no possible way a scientific research can be done that includes all the economy, there are simply too many billions of transactions and different combinations that it is impossible to do it. Some microeconomics studies can be carried out but only considering a single company or industry and few factors.

Economists must base their research upon past events and develop models that can predict future events. Sadly but true, even meteorologists have a higher percentage of correct predictions than economists.

The few good economists must be very good at math, history, politics, philosophy, psychology, developing abstract ideas and make them concrete ideas, and last but not least must be able to explain all of this to others and convince them.

The problem with applying economic models to the real world are the changing expectations of the general public (psychology and philosophy). One of my teachers had a great saying, "the mouth is the most sensitive organ in your body, but your pocket is by far the most sensitive part".