Expert for hire

An all-purpose expert is an oxymoron. Experts for hire, say for pay professionals, or rent-a-quote experts is a term used for those experts who trade on their legitimate credentials and professional reputation to bolster various claims, often outside their field of expertise, in return for money.

An expert for hire usually has these qualities:
 * 1) Is an actual expert, i.e. possesses a valid degree from an actual academic institution (and no, “Christian Education” and similar (pseudo)degrees don’t count).
 * 2) Is sponsored by a third party (for instance via a think tank or front group) to shill for them (i.e. not simply rambling on their own dime, such as cranks in general and the sufferers of the Nobel disease in particular).
 * 3) "Ideally" has a history of shilling for more than one third party. While the absence of this last type of mercenary behaviour is not necessarily a reason to exclude someone, its presence in conjunction with the first two can be taken as definite evidence of an expert for hire.

Tools of the trade (in more ways than one...)
The "expert" support provided by experts for hire can be in testifying at trials, such as the tobacco industry’s cultivation of "friendly witnesses" in the medical profession by the way of research grants in years past. Often the experts are paid by an attorney to render a professional opinion on research that is not mainstream and skewed towards helping the lawyer's case, as saying much more would be considered perjury. Experts for hire essentially rely on credential bullying, in that many people tend to give more weight to someone who allegedly spent many years of their lives educating and working in the fields in which they are are called to testify.

Note that those cranks, charlatans, and other mixed nuts who put the letters Ph.D. at the end of their name based on the toilet paper "degrees" doled out by various diploma mills and unaccredited theological educational institutions, often based on little more work than signing a check, are not experts for hire, since, well, they’re not actually experts in anything. If a credulous jury is swayed by such flimflam artists, that’s simply old fashioned bullshit artistry. Also, experts for hire should not be confused with " and similar terms — where the expertise of the person so designated is readily verifiable and is not compromised by the kinds of conflicts of interest already mentioned.

However, rather than (only) working the courtrooms, experts for hire more frequently operate a FUD media strategy, often disguised as "skepticism". If these experts for hire were serious about criticizing the actual science and engaging in normal scientific skepticism, they would, of course, be challenging the science through their own scientific work and publish it through the normal peer reviewed scientific literature. Instead, however, they will appear as talking heads on various media platforms, writing op-eds and speaking at various non-scientific conferences and similar events sponsored by their backers. Unfortunately, since most ordinary people rarely read peer reviewed literature, such a media strategy is often far more effective than heaps of actual scientific studies in (misin)forming public opinion — just look at polls of the US public perception of the validity, seriousness, and acuteness of climate change.

Spotting experts for hire

 * Their degree is not related to the field(s) they pose as experts in (e.g. a nuclear physicist speaking on the effects of secondhand smoking, acid rain, or climate change)
 * They have published little or nothing in the peer reviewed literature of the field they pose as an expert on
 * If they have published relevant, peer reviewed research within the field, the research is either very dated, controversial, marginal, has been subsequently disproven, or touches on peripheral issues, but will typically be touted as crucial refutations
 * They have only been employed in trials instead of work in their field
 * They have been removed from an organization in their field due to serious misconduct or falsifying records for their agenda
 * They can show no research, in progress or completed, to establish the data behind their opinion(s)
 * They have a history of appearing as experts on a wide variety of topics, way beyond what someone would plausibly be an expert on at the same time (no one is likely to be an expert on both climate change, secondhand smoke, and acid rain, given that each of these topics alone involves a variety of scientific disciplines. Thus, even a prodigious polymath would probably not be able to master all of the disciplines necessary to speak with authority on all three topics)
 * They spend far more time pontificating through the media than they do working on actual research (if indeed they conduct any research at all)
 * They are paid by well-known “think tanks” or similar lobbying/propaganda/spin organizations

Examples

 * The Heartland Institute — a hub for various industry-sponsored experts for hire
 * Richard Lindzen
 * Steve Milloy
 * Frederick Seitz
 * S. Fred Singer
 * The Advancement of Sound Science Center — founded by the tobacco industry as an expert for hire astroturf/front outfit