Lots of good answers, but with regard to the political ones, it strikes me that the condition applies in almost all cases to simplistic political policies or beliefs. Glossing over complications and costs is important to selling the policy, and proponents either know but are deliberately understating the complexities, or are naive and already sold on a sales pitch which does.
Eg. the push back posts saying raising the minimum wage to $15 would only increase a fast food burger by $0.10 and even increase employment…I believe the ‘studies’ they indirectly refer to (no cites) are about much more modest min wage increases. Studies of small increases have found it difficult to pin down effects on product costs or employment. But obviously at some point if you keep jacking up the min wage it raises costs significantly, and typically for items poorer people are more likely to buy (eg. fast food meals are a bigger % of poorer than richer people’s spending), and reduces low skilled employment. You can’t say there’s no change at $20, or $50. Likewise the impact of $15 isn’t likely to be similar in rural Kentucky as San Fran, and whether such a policy should be national one size fits all is topical.
There are costs to somebody else to mandate that wages be raised above the market equilibrium. ‘Studies’ aren’t going to show that’s untrue, because it’s axiomatic. The question is who pays those costs, or for example how they are distributed v. a policy which taxed higher incomes enough to fund a $7/hr govt subsidy per hour worked for people directly paid $8/hr. If you think one of those policies costs money but the other one doesn’t, you are just mistaken. And the distribution of who bears those costs and effect on employment wouldn’t be the same either.