So, going by the estimate of the cost of this year's payroll tax cut holiday, extending it next year would cost another $120 billion and adding on an identical employer-side cut would cost another $120 billion. So, that's another $240 billion.
To be clear, I think doing this is better than doing nothing. And doing something like this may be the only thing Obama can get from the Republicans. I get that. But that's, you know, "the compromise." And the problem with the compromise, as with the last one and the one before that, is that it isn't as good as the dirty hippie idea. It will not work as well as the dirty hippie idea. It may not work well enough. So a year from now... unemployment might still be high. And then we'll get more op-eds about how dirty smelly hippies had crazy ideas to build SUPERTRAINS and repair water systems and potholes or increase food stamps and aren't they stupid it's all their fault. Or something.
Using the power of multiplication and Klain's number, $240 billion in road repairs would give us 1.5 million jobs over two years. It would also give us repaired roads.