It’s been a long labour. Two years, two prime ministers, one interregnum, a bunch of prime-time ads, and a whole lot of negative headlines after the original conception, the government is pleased to announce they are the proud adoptive parents of a cute little resources rent tax.

Not that Ken Henry will be passing around the cigars to celebrate the arrival of this slightly stunted, more than a little mutated, version of his policy baby.

It’s not 40% anymore, it’s an effective rate of 22.5%, for starters, and only applies to iron ore and coal.

We now get the chance to see whether the repeated industry and opposition claims that the tax would be a disaster for the resources sector or whether — as we’ve seen with previous new imposts like the PRRT and condensate excise — the claims of apocalyptic impacts give way to silence and business as usual once it is in place.

But we knew the truth right from the moment the Rudd government announced the original, and allegedly more draconian, RSPT: the share prices of our biggest mining companies outperformed the market even as those of their international competitors were struggling.

So much for “sovereign risk”.

The entire exercise has been a lesson in the very worst aspects of Australian public life: greedy, lying mining corporations; a craven, focus group-driven government, a crassly opportunistic opposition and rank expediency on all sides. And in the end, the government is spending more on the associated measures than it will earn in revenue.

It’s one for the economic history books. For all the wrong reasons.