"You're just going to have to trust me on this one...I'm the one with the degree in Economics, remember?"
This was an argument I once heard from a liberal when I had the audacity to question the predicted results of a minimum wage increase. The general point of this was "I'm an expert, you aren't, so my opinions are above your questions."
This is different from true expert testimony, by the way. A true expert, when giving testimony, has to do more than establish their credentials by their vocation or degree, at least with a person who does not know enough about them to trust them at their word.
Often times, it usually focuses on education, rather than real world experience. Academics (that is college professors or researchers) tend to think their book smarts far outrank the real-world experiences of others. To give an example, having a degree in Economics often gives a person knowledge of Economic theory, but given the diversity of theories it doesn't necessarily give them understanding of what actually works in the real world (often it doesn't, actually). A person who has actually run a business understands more than a person who studies theories.
When it comes to the effect of a minimum wage increase on both the real spending power of a minimum wage employee as well as on the employer, I can claim real-world expertise. Why is that? Because I managed a national chain restaurant for a few years and oversaw a minimum wage increase. During that time, I saw the effect on pricing of our product and discussed how it effected some of my long-term employees (especially those who were actually making above the minimum wage because they earned raises).
I told this person that the real impact of the increase would be an economic drop because business owners would have to increase prices and cut hours. Further I explained it would be a real money loss to the employee who had already earned raises over minimum wage and a zero real dollar gain to those who were making the old minimum wage.
I was told my real-world expertise doesn't matter, because they had a study from an Economist that proved the increase was positive. The Economist quoted hadn't run a business. They just knew the theory behind the increase.
It's the same mentality that claims that Keynesian Economics works based on theory. Keynesian Economics doesn't have real-world success stories, just failures. If we were applying real-world success to our choice of economic planning we'd follow a school of economic thought like Supply Side Economics or the Austrian School of Economics, both of which have seen historical success.
Bottom line is this: Real world experience means more than theory, because it's been exercised in practice.