Expertise is about knowledge. There are two kinds of knowledge: knowing-how and knowing-that. Some knowing-hows require knowing a lot of knowing-that, but nearly all of us know-how to do things without knowing all the thats behind what we do. Do you know how fuel injection works? Doesn't stop you driving a car.
Expertise requires something that someone can be an expert at. There must be a stable body of effective practice, successfully-tested theory and facts. There can be differences of opinion, controversies and changes in this corpus. Too few and we should suspect a professionally-imposed conformity; too many and the subject stops being stable enough for expertise in it to be meaningful. What counts as too many or too few is itself a matter of judgement.
The subject must be manageable. It must be small enough for one person to get their arms round. If an expert is someone who know all the facts, or at least, knows where the facts may be found and absorbed quickly, then there can't be too many facts. Some subjects, like public health policy, or the dynamics of the climate, are just too large to be expert-friendly.
There are no expert witches, because there are no effective spells, and hence the theories have failed all the tests.
There are no experts on (the whole of) the Law of England and Wales. There are simply too many volumes of Halsbury's
Laws of England. No one person can get their arms around it. That's why lawyers specialise.
There are experts at medical diagnosis, usually within a specialist field: the facts are few in number, the theories are simple (compared to Quantum Field Theory), while the techniques may be subtle.
What about computer modelling? Three things go into a computer model: the model of whatever it is; the program that embodies that model; and the values of the various coefficients and initial conditions of the model. Those are three different subjects. To model the spread of a virus, one needs to know some immunology, some epidemiology, and perhaps all sorts of things about how close people sit in offices, how many people come within a given distance of others in the course of a day, and so on. Then someone has to take all that and put it in equations and computer code. Then one needs to measure the value of the key parameters for that virus. If those are not known, the whole thing is pointless. The result has to be calibrated against previous epidemics as a test. Journalists never seem to ask modellers about that part of the process.
This needs team-work. Teams cannot be experts. A team might consist of experts at parts of the process, but there is no guarantee that the team members will work well together. The result may well still be a camel. (A phrase that is unfair to camels.)
How do you and I tell if someone is an expert?
First, the subject must sound like a proper specialism. Immunology is a specialism, 'the climate' is not. Epidemiology is, but only when it is being modest.
Second, if they are quoting computer models, not empirical studies, they are not experts. Experts deal in facts and successfully tested theories.
Third, if asked, experts give practical, useable advice that helps the client achieve their goals - or admit that there is nothing they can offer. Pseudo-experts jump to publish research that a) seems to lead directly to policy advice, that b) is in line with their ideology, and c) politicians or managers cannot or will not follow because of
economic / social / legal / market / political realities. That last is essential. If what the politicians or managers do works, everyone's happy. If it fails, the experts can say that they advised something different. So they weren't wrong. They weren't right either, because their ideas are never actually put to the test.
Fourth, they do not use whatever it is to advance their social and political beliefs. Experts are not activists. Experts do not see our crisis as their opportunity.
Activists follow an ideology. Ideologies tell their followers what is right and what is wrong. There is no need to worry about facts or the quality of the theories and models: if it helps the cause, it's good, and if it doesn't, it goes in the bin. If the facts are different, that proves the world is corrupt and must be changed or burned down, not that the ideology is wrong. There is no debate, only persuasion; no information, only propaganda.
Activists are attracted to large subjects where there is plenty of ambiguity, complicated statistics, simplified computer modelling of complex systems, few if any opportunities to test any of the theories, and the appearance of relevance for social and political policy.
Once inside these subjects, activists aim to establish their ideology as the purpose of the subject: for example, if you don't buy Climate Change, you're not going to get a job in the UK Met Office. The central tenet of the ideology is binary: you are a believer or not. But in a twist known to everyone, one can't just pronounce the
Shahada and go back to one's life: one has to take on all the cultural baggage.
Or perhaps, one should not pronounce the
Shahada unless one is prepared to take on the cultural baggage. People who are not prepared to take on the baggage will avoid the institutions which demand adherence to the Thirty-Nine Articles of Religion, or their modern equivalents, and this is the intention. So much as naming the ideology on the website will deter the non-believers. Internal criticism is not so much actively silenced as recruited away. The old guard either stay quiet or leave.
Fifth, experts do not work in ideological institutions. Why not? Because of the risk they run should their research turn out to be contrary to the aims of the organisation. And because of credibility: once we know a man is being paid to follow a party line, we do not know if he is telling us to follow the party line because it is the best thing to do, or because his paycheque depends on it. Experts need their credibility. Activists just need to fill the air with noise.
So the next time you read an article quoting a piece of research about something in the news, that seems to have immediate policy relevance and fits in with a prevailing ideology, the authors are not experts, but a bunch of academics seeking their fifteen minutes of fame.
Because, sixth and most important, experts stopped talking to the media about the same time that journalists stopped reporting the news and started pushing ideology. Nobody who talks to The Guardian, or the BBC, is an expert. They are a propagandist for a dogma the media want to push.