So Phil Goff’s apologised for the light bulbs ,   a long with a few other things, but it’s the light bulbs that got our attention – especially because in the same paragraph he apologised for the high price of power.

Yes Phil, the light bulbs were a side show, but not for the reason you think. The trouble is not that telling people what light bulbs they can and can’t use is nanny-statism, it’s that it’s not the best way to make people cut their electricity consumption.

What’s the best way to ration a finite good? Well, one way you could do it is by giving everyone vouchers, entitling them to so many units of electricity. That way, those of us who preferred a bright incandescent glow could have one. Perhaps we might need to turn off our air-conditioning, or our hair irons. No problem.

Perhaps those who particularly valued the things electricity operates could buy vouchers from those who preferred a less energy-intensive existence. If we introduced the same system for water perhaps the odd-numbered houses could have Christmas lights while the even-numbered ones had water features.

Of course, what would inevitably happen is that we’d wind up with a flourishing secondary market for vouchers, which is why we usually skip the vouchers and use cash.

If we want to reduce the total greenhouse gases generated by electricity consumption, cutting the price is the wrong place to start. It just encourages consumption. In fact, make the price high enough, and who knows how low we might go .

Of course, if you’re living in the city, and you’re battling away on a low wage or no wage, your scope to generate your own power might be limited, but there’s a pretty easy way to fix that too. Here’s a clue: it doesn’t involve price cuts and it doesn’t involve vouchers.