More fun with numbers

The FT had already published one letter pointing out a glaring error in an article of last week; that letter itself contained a glaring error, as covered previously. They published a further letter from a fellow pedant today, pointing out another daft mistake in the original article:

Sir, Professor John Taylor writes in his fascinating analysis (“Exploding debt threatens America”, May 26) that “100 per cent inflation would, of course, mean a 100 per cent depreciation of the dollar. Americans would have to pay $2.80 for a euro”.

That seems wrong arithmetic [sic]. If the dollar depreciated by 100 per cent, it would be worthless. Would a correct statement not rather say: "100 per cent inflation would, of course, mean a 50 per cent depreciation of the dollar"? Then Americans would have to pay $2.80 for a euro.

Josef Bucher, Helsinki, Finland.