"It’s that once you’ve persuaded yourself of the merits of an argument, three cognitive biases kick in to play down trade-offs:
- Asymmetric Bayesianism. We tend to be more sceptical about arguments from the opposing side than from our own, with the result that a balanced presentation of the evidence increases our dogmatism.
- Wishful thinking. For example, those who value national self-determination want to believe that Brexit will also make us better off – and wishes often beget beliefs.
- The halo effect. We tend to believe that good things go together, even though they needn't. For example, attractive defendants are more likely to be acquitted than ugly ones. David Leiser and Ronen Aroch have shown (pdf) that this characterizes lay people’s thinking about economics. They show that non-economists apply a “good begets good heuristic”: they tend to believe that good things lead to other good things.
Berlin went on to write that those who deny trade-offs rest on “comfortable beds of dogma”. He should have added that such beds are easy to make."
Stumbling and Mumbling: Not seeing trade-offs