Why are National squealing so loudly about a capital gains tax? Look at how many houses they own, says Newsroom. Their article details the blatant conflict of interest of most National MPs, who are loaded with hoarded houses and business investments - all of which would be subject to a capital gains tax. So it seems a bit... self-interested of them to be speaking out against it, neh?
Unfortunately, what's obvious to the public is not obvious to Parliament: its Standing Orders define financial interests only in terms of benefits (rather than avoided costs). Further, they explicitly exclude "any interest held by a member or any other person as one of a class of persons who belong to a profession, vocation, or other calling, or who hold public offices or an interest held in common with the public", and do not require interests declared in the Register of Pecuniary Interests to be specifically declared to the House before voting. The net result: Standing Orders think it is fine for MPs to vote to keep taxes on themselves low, despite the fact that they could be benefitting by tens or even hundreds of thousands of dollars from the vote.
There's a word for this: corruption. And our parliament has institutionalised it.