Real economics vs slogan economics

Does it really matter if your economic policies are based on as close to reality as social science ever comes, or slogans and ideology? Paul Krugman says it does.

The simple fact is that we have a global excess supply of savings, which is doing terrible things to workers. The reasonable thing is to do something about it; it’s deeply unreasonable, and deeply irresponsible, to invent reasons not to act because you’re clinging to simplistic slogans.