You can have cheap pensions and you can have interventionist pensions

But you cannot have cheap and interventionist pensions investment. That combination being what The Guardian is demanding:

Indexation keeps charges low – Nest is fantastically cheap. There are lots of good reasons to spread your investments over a diversified range of international companies, which Nest is doing. What’s more, in achieving returns of 10%-plus a year since launch, it hasn’t had to face too many awkward questions.

Nest is cheap, that's the way it has been designed. And the only way to have it that cheap is to be sticking the money into low and no load index funds. Any other system would mean having to cream off substantial parts of any likely return for those who do the managing to make the return. In fact, that's rather why Nest was first designed: to make it quite clear that there was a way of gaining pensions savings without having to pay over all of the gains to the Men In The City.

All of which is fine but it's entirely incompatible with this next demand:

Conventional City of London ideology is informing its investment decisions. Yet in Singapore, the country’s compulsory pension fund has been mobilised to held build local housing. Ottawa’s pension fund is extraordinarily interventionist. Given that we will be throwing hundreds of billions of pounds into a pension scheme for British workers, could we at least have a wider debate before sending half of it to Wall Street?

We've had that debate. And the answer was that we'd rather not send 2 and 20% to hedge fund operators, one or two percent to more traditional fund operators, for we've noticed that those fees almost inevitably eat up, and more, any extra performance they produce. And that's why all of these schemes for different methods of pension savings crash into a brick wall set up by reality. Yes, even these ideas that pensions should be in bonds to pay for infrastructure. The extra costs of managing the money, the extra costs of the requirement to have the people managing the money, are greater than the increased returns from having done so.

That's why indexation. For you can have pensions with cheap charges and you can have pensions with interventionist, active, management strategies, but you can't both pay for the activity and also have a cheap pension.