How is one supposed to determine whether somebody is an 'expert' at some discipline without having expertise in the field in question themselves? And, why automatically assume some academic is anything besides just another crank? Credentialism is meaningless as indication of anything, especially in an area like economics, a modern version of astrology and entrails reading at best, complete fantasy at its norm these days, with some exceptions in the econometrics field. Most of the unwashed don't realize just how much backbiting and egotism dominates academia in most fields, and just assume they're all competent, objective professionals. They aren't.
Red:
One doesn't necessarily need to determine whether a leader is an expert. One need only figure out if they are more, equally or less capable analytically and more knowledgeable in general than is oneself. To do that, one need only obtain from the would be leader an assortment of substantive remarks, listen carefully to them, and then seek out objective information to determine whether what they say "holds water" or doesn't. By doing so, one acquires new knowledge of one's own as well as discovering whether the would be leader knew what they were talking about when they uttered their remarks.
Blue:
Nobody needs to assume any academic -- academics aren't, by the way, the only experts on the planet -- is a crank or not a crank. One need only review their published ideas and the methodology they used to arrive at the conclusions they articulate. The key is not to find one or some minor error(s), but rather to find errors that are material enough to invalidate the conclusion. Absent finding such errors, regardless of what the writer says about other things, what s/he said about the topic in question is valid. Truly it doesn't even matter if the writer is an academic or isn't. What matters is the strength of their observations, tests, analysis, and findings.
Pink:
??? I bid you look at the predictions that economics makes and then perform a test to see whether those predictions hold true. Economics is a social science. The science part of that description means that it's
theories must be testable and
falsifiable. Astronomy and entrail reading's predictions and theories do not in any way consistently pass that test.
Green:
Most of the "unwashed masses" don't and won't bother to actually read the documentation researchers provide to determine whether any given study was or was not objectively conducted. Believe it or not, and if you don't read scholarly papers, I suspect you don't believe it, the reason researchers explain their approach to performing any research they share publicly is so that others can examine the whole of their process to gauge for themselves whether the study was competently and objectively performed.
You or I can read the documentation just as readily as can anyone else. If we don't understand what we read, we have no place, no right, to say there's something wrong with it. If we do understand what we read, we have an obligation to ourselves and the writer to say precisely what it is we find in error. What none of us has the right to do is arbitrarily assert "this or that" is or is not so based on the anecdotal observations and evidence that's come our way. To do that is intellectually irresponsible, to say nothing of disingenuous.