 On 17 August 2012 the BBC Radio 4 program "More or Less" noted that the Carli index, used in part in the British retail price index, has a built-in bias towards recording inflation even when over successive periods there is no increase in prices overall.In 1738 French economist Nicolas Dutot proposed using an index calculated by dividing the average price in period "t" by the average price in period "0".In 1863, English economist William Stanley Jevons proposed taking the geometric average of the price relative of period "t" and base period "0".