It's the same as with the cash for clunkers program: in the end, there will be a slight increase in the number of new people hired by eligible small businesses, but we'll end up paying a lot of money for it because all the other ones that were going to hire anyway are also getting the credit.
The correct measure of success for a program like this is not how many were hired during a specified period, it's how many were hired over and above the number that would have been hired had the program not existed. Then you see how much each incremental hire really cost. It's not always a cut-and-dried analysis, but in the case for cash for clunkers it showed that we got ripped off. This will be similar.
At the least, it's a rare tax cut for small business, instead of them getting the scraps or having theirs increased.
