Following Labor’s thumping election victory, attention has turned to the government’s years-old proposal to tax unrealised capital gains for super accounts with balances over $3 million, for which it now has an electoral mandate. That most people have waited until after the election to question whether this is a good idea is puzzling.

Principles are important for building a coherent framework. A coherent framework is important for building coherent policy. Incoherent policy is bad for two reasons. It distorts behaviour, sucking up the economy’s resources, making us poorer. And it generates horizontal inequity, treating otherwise similar individuals differently, offending our basic moral sense of fairness.