These findings might also be useful for choosing between high-variance and low-variance careers, insofar as you are able to predict how much better at each of these skills you are than average.

For example, engineering is a field where most people earn a decent wage and some people earn a very decent (but not obscene) wage. I think the average salary of an engineering graduate is about $58,000, with the vast majority of that made up by people working in the $30,000-$50,000 band with a couple of hotshots pulling down six-digit salaries and almost nobody grinding out a subsistence wage. By contrast writing a book is a field where one or two people become megastar billionaires like J K Rowling or John Grisham and everybody else earns practically nothing. Pretty amazingly (I think it’s amazing) the Bureau of Labour Statistics reckons the average wage for a writer is almost exactly the same as the average wage of an engineer ($56,000), but it seems likely to me the median salary is much lower than in engineering (maybe something like $15,000-$25,000) with the mean heavily skewed by the handful of super-rich authors.

What this suggests is that you can – on a probabilistic basis – determine whether you are likely to end up at the top or bottom of the income distribution of your chosen profession. If you know your political knowledge and skills are weak, it would be a good idea to pick engineering over writing (assuming you are equally good at both) because you are more likely to end up earning $30,000 than $100,000. If you are excellent at office politics you are much more likely to form the sort of connections that give you a bestseller, and so writing might offer you the highest expected earnings even though the average salary in both professions is (nearly) identical.

This is complicated by the fact that ‘political knowledge and skills’ are not consistent between careers (the most insensitive politician is likely to be far more manipulative than the smoothest political operator in database administration), but I think it is probably possible to allow for this and still have more information about career choice than you did before.