It would appear that Tyler Cowen, Greg Mankiw, and Matthew Yglesias all agree with Christina Romer that manufacturing isn’t special. Following the policy of not treating manufacturing as special has led to . . . the US steadily losing manufacturing jobs. But don’t worry, I’m sure it’s not the theory is that’s wrong.
If I had to make the argument that manufacturing was special for a few reasons, I’d argue:
1) From the viewpoint of a nation-state (at this point I’m aware that I’ve lost all mainstream economists, since borders seem "random" to them, but everyone else over the age of 4 should be able to follow this argument – economists may skip to the second point) manufacturing jobs seem to be zero-sum (there may be two jobs in China for every one in the US, or whatever, but some country is getting those one or two jobs and all the others are losing those jobs).
The fact that Steve Jobs creates Apple in California may be positive sum, but once Apple is created, someone is going to make iPhones. It’s either your country or another one.
On a related note, manufacturing jobs may be special in the sense that many many countries are willing to protect and subsidize them.
2) Manufacturing jobs are labor and capital intensive. We want people employed in serious, long-term occupations – not drifting from one Fed-induced bubble job (trading tech stocks to underwriting mortgages to digging for commodities to whatever) to another. I’d much prefer paying slightly higher prices for good and services than paying higher taxes for welfare benefits. Either way, I’m poorer, but the former way at least employs people instead of putting them on the dole. Also, industries that employ lots of people and require lots of capital would seem to be more hindered by regulations than other sorts of industries.
3) Manufacturing seems to be highly path-dependent, in other words new manufacturing jobs may only be viable in locations that currently have related manufacturing jobs. If you starting losing manufacturing jobs today, you’ll lose the manufacturing jobs of tomorrow as well.
Those are the obvious reasons (to me, at least) why manufacturing might be different. Unfortunately, Romer doesn’t consider any of them.