why has the RBA selected an inflation target of 2-3 per cent, rather than 0 percent?

Question

just reasons. :)

Answer 1

In short, a little bit of infliation is good for the economy, but 0 inflation actually hurts the economy, because it essentially caps prices and profits and makes it hard to increase employment. Worse, if 0 inflation turns into deflation, then it starts to negatively affect wages and economic output, creating a vicious cycle.