With respect to 2%, what is very clear is that you want a rate of inflation that is low, and in terms of delivering it, you want to focus on low, stable, and predictable.
There are some good reasons you might not want to go all the way to zero. Since renewing the target at 2% in 2006 there has been a considerable amount of research looking at what would be the best rate of inflation. On balance, I would say the research tends to suggest that it might be a little below 2%. Having said that, it's certainly clear that 2% has worked very well. Our economy has performed well. Our macro-management has been quite successful.
So it's a high bar, and I think you'd want to consider carefully the success we'd had before you made changes.