Slate: A Secret Tax on Teenagers, by Tim Harford:

Britain’s chancellor of the exchequer, Alistair Darling, did something rather strange recently to baffling applause from his own supporters and cries of "bribery" from the opposition: He announced a tax on teenagers.

Darling’s plan is to cut income taxes temporarily for all but the most prosperous taxpayers. The apparent windfall is £120 each—almost $230. If that sounds familiar, it isn’t surprising: A similar plan is already in motion in the United States, where a temporary "tax rebate" began to arrive in the bank accounts of a grateful nation about a month ago. The motivations are different in the British case. While the U.S. plan is billed as an economic stimulus, the British plan is marketed as compensation for those who lost out when taxes on some low earners were recently raised. No matter, because the practical impact of both plans is just the same: Teenagers are getting it in the shorts.

Here’s why: Since neither the U.K. nor U.S. government intends to alter its spending plans, these tax holidays will be funded by government borrowing, borrowing that must eventually be repaid. That will require taxes to go up in the future or not to fall when they otherwise might.