‘Carey is convinced that one of the problems with government e-services and digital systems is that they try to replicate analogue systems in a digital environment. For example, digitising a 36 page analogue form and expecting people to fill it out, resulting in “appalling” completion rates.

‘“That may mean simplifying the tax system, for instance, or the benefits system,” he suggests. “You may have to round up some benefits and tax bands for rough justice, but you would save so much money if you did it.”’

That set me thinking.

Imagine if the complexity of personal tax assessment was fixed by an upper limit on the number of questions that could be asked – particularly if that number was based on measures of completion rates and data cleanliness. It would force an outside-in customer-focussed system design. Economy of flow would be driven right through the system starting from the customers’ perspective. It would discourage well intended but centre-driven tampering with the rules: if a new rule requires supplementary questions, a counter-productive (and measurable)cost is paid through added complexity to the form.

If my kids can identify most things in the universe by asking twenty questions on a long car journey, it should be possible to make a just assessment of tax from a limited set of questions.