Dirty dairying and moral culpability

Gareth Morgan and Geoff Simmons have a piece on dirty dairying in the Herald today. The first of two parts, it looks at the economic reasons why farmers are destroying our rivers. And this boils down to two things: no taxation on capital gains, which encourages dairy conversions so farmers can profit from the increase in land prices, and a whopping externality around pollution, which sees farmers able to pump shit into our rivers without paying a cent. Combined, these mean massive effective subsidies for environmental destruction. So much for our "subsidy-free" dairy industry.

But then there's this bit:

Let's be clear up front; we aren't blaming the farmers. Like the bankers in the GFC they are just responding to the incentives the market presents them.

Sorry, but "responding to market incentives" is not a moral free pass. If I offer you $100 to kill someone, you're still a murderer if you take it, no matter how much you plead about "market incentives'. And the same is true of bankers and farmers. Obviously we should fix the incentive structure, so that it discourages selfish, immoral behaviour - but that doesn't make people who follow the incentives any less selfish or immoral. If farmers get rich by taking taxpayer subsidies to pollute our rivers and destroy our environment, they fully deserve our moral opprobrium and condemnation.