We can learn a lot about the discipline of economics, the thinking of its practitioners and the limitations of ethics codes by reading the various reactions of economist to the question, “Do economists need a Code of Conduct?” The responses range from “yes” to “sure, but it won’t do any good” to “no.”
You can read all about it here.
Ethics Alarms 
I would vote “It doesn’t matter”. The First Law of Economics seems to be “for every economist, there is an equal and opposite economist”. I did like the argument that the problem is that there is ethical conduct in the economics journals, but that is relatively unimportant because the importance of economics lies in the government economist, who is beyond ethics rules.
Michael makes a point. Economics is an inexact science- like psychology and meteorology. It can claim to being a science to the extent that its precepts can be expressed in figures… which is the dividing line between science and art. However, like those other two, economics covers such a broad field and relies so much on hypothetics that, in practice, it’s little better than an educated guess. Unfortunately, in its case, those “guesses” are also influence (and are influenced by) outside considerations, such as politics, money and personal ego! Therefore- and as with all professions that intrude into the public realm of discourse- I think a code of ethics should be in place. In fact, any profession that maintains an organization with members- and is therefore representative of that profession to the public- should (if only in the preamble to its charter) post both a mission statement and basic rules of professional conduct. And enforce them among its members. Otherwise, that profession devolves into a grab-while-the-grabbing’s-good collection of misfits.