As a proportion of taxpayers, how many would have that pattern? Should the tax system be optimised for that proportion?
And it's a no-win situation - how do you prove how long you've been working on a project? How outraged would people be to be back-taxed? After all, if you want to spread your taxes over previous years, you now need to pay more taxes for those previous years. And how do you differentiate between a 'lucky windfall' earner, and someone who has simply engaged in a lucrative new career (such as students moving into professional careers)?
The difference in marginal rates is noticeable, but not crippling, and this 'lucky windfall' pattern of earning is not very common.
And it's a no-win situation - how do you prove how long you've been working on a project? How outraged would people be to be back-taxed? After all, if you want to spread your taxes over previous years, you now need to pay more taxes for those previous years. And how do you differentiate between a 'lucky windfall' earner, and someone who has simply engaged in a lucrative new career (such as students moving into professional careers)?
The difference in marginal rates is noticeable, but not crippling, and this 'lucky windfall' pattern of earning is not very common.