An excellent and relevant example of why the economics profession is far, far from being any kind of a science... its even questionable (to me) whether it can even be considered a valid social science. The example is just one of many others. There are a multitude of differences in definition (or lack of agreement among economists) of even some of the most commonly thrown about economic terms.
What this tells me is that the "economics" profession as an academic field of study has no disclipline within it's own community. The lack of discipline means that the field has no sound foundation (from the get-go) upon which it has been or can be built... therefore enabling the field to be many different things to the members of the community. This actually promotes the lack of discipline, hence the lack of common and accepted objective definitions.
One should therefore ask why the lack of discipline persists even after a couple of centuries of academia in the field? The answer has to be that it must therefore serve the interests of those in the field and/or those that use the resulting variety of contrasting academic output to serve their own contrasting interests.
Just a cursory review of the major pieces of academic literature and major academics over the past century or so illustrates the variety of conclusions, hypothesese, & theories. They can be summarized by the socio/political terms conservative & progressive... each varying only by degrees. Methods used by the physical sciences are used to support one or the other of these contrasting socio/political views of how the economic world works (or should work, depending on your point of view), though these methods are applied only loosely --- showing correlation of variable A to variable B for example and then extracting "causation" conclusions therefrom, though causation is not in any form established scientifically or just even agreed. Theries and hypothesis are proposed for which there is no means of testing the validity of either... even in some cases by definition of the theory or hypothesis itself (an example of effective circular reasoning).
The perennial excuse for this is that controlled experiments cannot be used to distinguish between hypothesis with merit and those with none... wihch is also the fundamental reason (excuse) cited for not being able to use scientific methods to test the variety of proposed hypothesese. This condition obviously serves the interests of continuing the socio/political debate in the field of economics.
This leads one to conclude the following:
- A field of study in which hypothesis cannot be rigoursly tested (regardless of the reasons) and repeated can't be considered a science in the understood sense of the term.
- A field of study in which the participants cannot agree on even the most fundamental of objective criteria in definitions (after a couple of centuries of existance of the field of study) cannot be considered to be a disciplined "study" in the first instance.
- If not a disciplined field of study then it's an undisciplined field of "study"... but "study" implies some form of discipline is involved.. a set of rigerous rules constituting the foundation & basis of "study". Since the field has remained and is still highly undisiplined then it can't actually be defined as a field of 'study'.
- If economics can't be considered as an objective field of "study" then it's not a "study" of economics. Rather, those fields of academic interest pursued but which aren't disciplned "studies" are better described as philosophies or the arts (drama, the physical arts of expression --- writing, painting, sculpture, etc).
This is not to say that some economists don't strive to insert discipline in the field, or to use strictly objective criteria in definitions, and hypothesis testing to the degree they can. But without a strong consensus and enforcement of disciplines within and by the field's participants they strive in vain.
That there remains no strong consensus within the field after at least the better part of two centuries only means that there is a strong negative incentive to establish one.. .which is to say in other words a strong incentive to retain and promote the lack of consens. I submit therefore that the strong incentive for the continued lack of consensus and discipline is directly due to socio/political interests that use the "study" of economics to serve their own contrasting interests.. and scientific methods do not necessarily serve the interests of at least one side of the contrasting socio/economics proponents. One guess about which side it serves.