With elections looming in many parts of the world, investment in children, themselves non-voters, competes with other priorities and a search for a winning ticket. But where do big ideas come from? A key driver of policy interest in the early years was a 1960s experiment1 in Ypsilini, Michigan designed to see whether access to high-quality education would have a positive impact on preschool children and their communities. In the UK, it came to the attention of the Home Office in the 1990s, perhaps because years on, lower adolescent crime rates were reported in the intervention group. A healthy return on investment of around US$7–12 for every dollar spent was claimed2—a metric with a powerful message. Coming at much the same time as the Campbell Collaboration, sister to Cochrane, was gathering steam in the social care and education fields, it hit the sweet spot for policy makers in the UK. Launched in the UK in 1998, Sure Start3 was the ‘big idea’ intervention designed to improve outcomes in the early years. Since then, it has had a rocky road.

At the very time that ‘evidence-based’ was finding its way into policy-speak, it made sense for a programme targeted at preschool …