There is to some degree in tension between economics and ethics, another of the most basic social sciences, which tends to avoid quantification and emphasize balances of rights. Modern economics deals with this tension explicitly - according to some thinkers a theory of economics is also, or implies also, a theory of moral reasoning. One way economists deal with this is to qualify discussions of economic choice by noting that "all else being equal..." referring to moral or social factors that are supposedly held equivalent for all choices that one might make. For exploration of this issue, see the moral purchasing article.

Another premise is that economics fits within a finite ecosystem where there are at least some abundant resources - for instance, when fueling a fire one is usually concerned with finding the wood, and not so much with finding the air to burn it with. Economics explicitly does not deal with free abundant inputs - one criticism is that it often conflicts with ecology's view of what affects what. Human beings are, according to ecologists, merely one species participating in a vast energy system on this planet - economy is a subset of ecology that deals with just one species' habits and wants. See nature's services for the economic view of ecology and green economics for the view wherein economics is a subset of ecology.

A third premise is that economics suggests market forms and other means of distribution of scarce goods that do not just affect "desires and wants" but also "needs" and "habits". Much of so-called economic "choice" is involuntary, certainly given the conditioning that people have to expect certain quality of life. Much of the welfare state that developed nations have built has no basis whatsoever in the study of economics in academia. This is viewed as a failure to respect economics by libertarians, and viewed as a failure of economics to respect society by socialists. This led to both 19th century labor economics and 20th century welfare economics before being subsumed into human development theory.

The debates above are all quite old. The term economics was coined in around 1870, and popularized by influential "neoclassical" economists such as Alfred Marshall. Prior to this the subject had been known as "political economy" and referred to "the economy of polities" - competing states. The older term is still often used instead of economics, especially by radical economists such as Marxists who strongly question assumptions of "mainstream" technical and quantitative economics. Use of this term often signals an intent to challenge or reframe economic assumptions about scarcity.

Some mainstream universities (such as the University of Toronto and many in the United Kingdom) have a political economy department rather than an economics department. Political economy explicitly brings political considerations into economic analysis and therefore tends to be more normative - for instance it would describe assumptions in common between green politics and green economics rather than assuming the latter objective.