India, Feb. 6 -- Budgets will come and go. Most are deficit, though a few are surplus. And the odd one is interim, while most are annual. Others are about continuity and change, as Prime Minister Modi has said. But none are like the budgets of William Pitt the Younger, who became Britain's Prime Minister at the age of 24, remaining in the same job for 22 years until he died at the post, fighting Napoleon Bonaparte.

Pitt's budgets were not only surplus, but surplus with a vengeance for, his objective was to build up such a large surplus in the British treasury that the United Kingdom could live off the interest earned on the wealth of the treasury. The British people, in such an eventuality, would not have to pay tax ever again. William P...