If the buyers and sellers in each market take their decisions following only their own self-interest, economists will not need to think of the wealth and welfare of the country as a whole separately. Which economist believed in this?

Adam Smith

The correct answer is option 1: Adam Smith

Adam Smith, a Scottish economist is associated with the concept of the "invisible hand" in economics. He argued that if individuals act in their own self-interest in competitive markets, guided by the pursuit of profit and personal gain, the overall welfare of society would be maximized as if by an "invisible hand." According to Smith, the pursuit of self-interest by buyers and sellers leads to efficient resource allocation, increased productivity, and overall economic prosperity. Therefore, economists would not need to think of the wealth and welfare of the country as a whole separately, as the actions of individuals pursuing their self-interest would naturally lead to beneficial outcomes for society as a whole.