As I write, we have a new Parliament in place, a new Government starting to govern, and a new policy agenda emerging. It's encouraging to see a renewed focus on prevention, including work by the Chartered Institute for Public Finance and Accountancy with the Health Foundation and the Institute for Government and the new health secretary recognising good health and care as engines of economic growth. We've even seen calls for a new category of Government expenditure, the preventative departmental expenditure limits, delineating clearly public sector prevention spend.

I've written before that spending ‘upstream' on prevention sounds intuitively cost-effective, but there have been challenges in evidencing this to overthrow Treasury orthodoxy. This stems from three issues: first, a time horizon challenge, where investment today won't result in returns until many years ahead. Second, an organisational incentive challenge, where the institution making an investment isn't the one where savings accrue. And third, the unmet demand challenge, where however much demand is forestalled, there is always more in the system – what I call infinite queue theory.