"Psychologists call this 'cognitive dissonance' - the ability to make a heartfelt case for one thing while doing another."
If I am reading the Economist piece the right way, then they seem to be saying that cognitive dissonance is about being able to do something that you have previously argued against (or something like that). In other words the ability to not care about (or perhaps even not be able to 'see') the inconsistency between an idea and an action.
If my understanding of what they are trying to say is correct then I think that gets the idea the wrong way around. As I understand it cognitive dissonance is actually the uneasiness we feel about two ideas that are apparently in conflict. For example the uneasiness I might feel about the apparent conflict between my belief that The Economist is a good and reliable source of information, and my belief that they have misunderstood a given psychological term. If you think about it, it ought be quite clear that it's about conflict in the mind when you think about what 'dissonance' means on its own.
I like reading The Economist as I find it quite challenging given its pro-market liberal stance. So it's nice to know that even they get things wrong.