It's not so easy, and some serious thought needs to be applied.
If I have $4m on deposit, I can decide how much I spend each year. And with current low interest rates any income would be low enough that I would not pay any tax. If I decide to withdraw $200k a year there would be zero tax - agreed?
Now if my $4m is in a SMSF, I'm forced to take out, say in the early years, $200k (5%). If I had to pay $30k in tax then how would this be equitable with the former situation?
Secondly one would have to take into account the taxable element of a SMSF. If my SMSF is 80% not taxable (represents the $ put into the super fund), then to tax this again would mean folks are paying between 30 and 45% tax on those funds - up to 30% on the way in and 15% on the way out. Again a most inequitable situation.
The only way to stop folks withdrawing all their super and going overseas / spending it etc would be to stop capital withdraws in an instance. No political party would have the balls to even think about it. Thus legislation to tax super would have to be carefully crafted in order to avoid a complete mess.
IMO, the equitable way would be for income to be taxed based on the taxable element of the fund. For example if a 5% draw-down is $200k, from a fund that is 50% taxable element then only $100k should be in play. If only 20% of the fund was taxable then only $40k should be in play. These amount could be taxed at marginal rates with the standard tax free allowance that every tax payer gets. The rationale is that the tax free element in a super fund represents the funds applied and not investment earnings.
I'm sure there are additional aspects that require consideration, but a simple %15 tax rate on all income from a super fund is just political grandstanding and opium for the media.
