...over the next ten years.

The trend toward stating government expenses and project costs "over the next ten years" is insane and misleading.

I have even seen it starting to crop up in contexts projecting not cumulative income or expenditures, but in results five or ten years from now.

First, no one knows what is going to happen next week, much less next year, or ten years from now – not to mention the fifty years frequently mentioned. How close were folks in 1960 to projecting our particular future? Such statements simply create a false sense of certainty about the unknowable. While we must plan, we must also recognize uncertainty. It is almost as if uncertainty increases (with length of time involved), people's desire to pretend otherwise increases as well.

Second, changing the time base for periodic expenditures distorts the ability to compare amounts (just as does use of the word million, billion, and trillion – and shortly to come quadrillion – instead of using strings of zeros or powers of ten). People's brains just don't work that way, even if they have a high degree of numerical sophistication.

Quick, how much is more: $10 million a year for the next ten years, or $100 million over the next ten years? The natural reaction is that the latter is more, when actually it varies from less to much less than the first, depending on assumptions about discount rates and inflation.

Delusion is a source of suffering, and use of "over the next ten years" invites delusion and distortion.