If all the economists in the world were laid end to end, they would not reach a conclusion. The “battle of the letters” – two letters in the FT, from Lord Skidelsky and others and Lord Layard and others, replying to a letter in the Sunday Times from Professor Tim Besley and others – brings this hoary joke to mind.

Thus, the Sunday Times letter argued that “the government's goal should be to eliminate the structural current budget deficit over the course of a parliament”, instead of the two planned by the government. In response, opponents argued that it would be foolish to slash the structural deficit if this led to a deeper recession and so to an offsetting rise in the cyclical deficit.

Yet both groups might be right. A book on inter-generational (in)equity by David Willetts, a Conservative shadow minister, and the green budget from the Institute for Fiscal Studies have clarified the issues for me: the answer lies in the growth.