I wrote this glossary originally because I found it hard to get all the definitions of formal terms in research economics from textbooks or classes. Now I see that the research literature often refers to terms I don't know that are not clearly defined. It seemed to me that a source was needed in which all the technical terms were defined clearly, in declarative sentences, without much spin. So I wrote one. On the Web we can all use it, share it, and hopefully come to a consensus on its best use, and organization. I invite input -- corrections, additions, reorganizations, or terms that one might think need to be defined but can't find a proper definition for.

There are many aspects one might want in a definition: clarity, usefulness, standardization, accuracy, brevity, completeness, and precision. I seek all of those, in descending order! To achieve a standard, clear definition I am willing to sacrifice a little accuracy or precision, in principle. I invite differences of opinion on that.

Definitions which quote any source at length refer to that source. Most definitions are standard in the sense that at least three source works give a similar definition or use the term without attribution, and for these no source is listed. Please do send corrections if I have failed to attribute a quote or critical idea.

What terms are in here? The guiding principle is that any term used in any English-language economics research journal that is neither defined there, nor common vocabulary among the mathematically literate belongs here. This is a broad, inclusive list, because it seems that a glossary is more useful that way. There are many terms from mathematics, statistics, sociology, and so forth. Abbreviations of government agencies are included if they seem to be relevant. The names of other institutions, or for that matter, people, are not usually in here. Maybe they should be. Your comments on this are welcome.

How much content is in here? Many definitions just say what an abbreviation stands for, or say that a given term is a synonym for another one, so the actual number of useful or "complete" definitions is lower than the 1200 or so entries.

A comment on tone. Academics are often a bit resistant to giving a clear, unambiguous definition of terms within their own subfield. To do so may take away some of the joys of insider-talk, or takes the fun out of the mysteries of their own field, or requires confronting assumptions that they'd rather not confront. Since that approach cost me so much when I was a beginning graduate student, I have tried hard to avoid it here, and it leads to what may seem to be an odd tone -- heartless, humorless, flavorless, explicit, and tolerant. That's on purpose. Any jokes or opinion content should be in square brackets, marked as editorial by [Ed: xxx]. It is unimportant, here, whether I like or don't like some term, assumption, model or way of thinking; the purpose of a glossary is to decode what writers using the term in the field mean.

Some of the sources cited are off the beaten track, rather than the major authoritative sources one might expect. Partly this is for the same reason -- a person who finds subfield A to be full of joys and mysteries may not be able to give a brief and clear account of it. Whereas the same person may be able to give concise definitions for subfield B which is a bore but which one just has to know intimately. So, for example, [warning, opinions follow] it's been tough in my experience to get enough really clear, declarative statements about real business cycle theory, human capital theory, general equilibrium theory, or nonparametric statistics from true believers. The ideologies of these subjects work too well for them. It's like a fish trying to define water or [warning, opinion follows] a pig defining slop.

Setting any opinions of mine aside for the moment -- that, above, is my explanation of why these definitions often don't come from the authoritative sources, but rather from an obscure paper where an author was just trying to say something clearly and briefly in his rush to get to something more fun which he could then say unclearly.