Do you remember under the halcyon days of David Cameron, when the Government was obsessed by the concept of this book?
Which basically says, rather than be a pure busy body nanny state and tell people not to eat bad food, you can create incentives via taxes or social signals that overall will change behaviours. It seemed great, less money could be spent, the Government could still play a role a nanny, but in a less authoritarian manner - so perfect for Cameron's continuity New Labour governing style.
We now have a really good example of this, the vote to Leave the EU in large part about the concerns around immigration - check out some of these ONS truth bullets that confirm why people were indeed concerned:
"Last year around one in seven residents were born abroad, and one in 11 had non-British nationality.
Another dataset released on Thursday showed that more than a quarter (28.2%) of births in England and Wales were to women born outside the UK, the highest level on record.
Statisticians said that despite an overall decline in the number of births between 2015 and 2016, births to mothers born overseas increased by 2.1% as foreign-born women make up an increasing share of the female population of childbearing age.
Brent in north-west London was the local authority area with the highest percentage of births to non-UK-born women, at more than three quarters (76.0%)."
So we voted Leave, a big social signal. Here we are 12 months later an indeed EU migration has fallen and emigration has increased. A net fall to a still unsustainable +246,000 a year - still a new Norwich or Blackpool or Milton Keynes every year.
But the 'Nudge' has worked hasn't it - immigration from the EU is falling after we have voted to leave the EU. At last, Cameron and his acolyte Steve Hilton have proof that the ideas they put into practice actually work.