I do think there is some validity to your arguement. I must say that it makes me very nervous to know that federal fiscal policy is tweaked based on a number that is derived in a similar manner to that of the polls that miscalculate who is going to win an election by as much as ten points.
Okay, let's say our unemployment is 5.4% plus or minus 4%. I feel much better.
I see your point, but the number of people working in any particular sector aren't necessarily a good gage to set fiscal policy on either.
You see a dip in the buggy whip sector jobs & you might want to give that sector some help, but is it wise policy?
The manufacturing sector has been going downhill since the mid to late ninties (talking about number of people employed doing the activity), depending on your source. A lot of people think that's due to outsourcing, which might be true in some sectors, but in truth, as a percentage of activity worldwide, it's dropping as a whole. We just do not need as many people to produce our widgets as we used to need & by we, I'm talking about the whole world. The countries that have gone after better environmental standards have made smokestack industries less welcome. Does the US want them back? Is the US ready to make them economically feasable, which may mean dropping environmental standards?
You might argue a protectionist policy, where you want the jobs, force high environmental standards, but find yourself with a tradeoff in higher prices leading to a reduction in the amount of stuff people can buy, which then leads to people out of work. Japan tried it & it seemed to work great for them for awhile, but it didn't last. Europe is sort of trying it now, but US productity & monetary policy are giving them fits, as are some 2nd/3rd world countries coming in to compete against them.
Meanwhile, while Japan was riding high, we (the US) dabbled in the "new economy" & then poof, the tech bubble burst. The old fashioned business model didn't seem so bad & stupid after all. But we have that dump of trained people expecting to go back to jobs in fields that exsisted on steam. They see their jobs as having been outsourced too, as during the growth of the bubble, it was learned that it was even easier for information to travel across borders, than it was for hard manufactured goods. That genie is just not going to get stuffed back into it's bottle again.
As far as doing a lot of tweaking of our economy, I lean heavily towards Classic theory, though it can seem more brutal in teaching people through their blunders, than those who like Keynesian theory dabbling. Having a bit of doubt might make those Keynesians a bit less bold in how much futzing they do.
People showing up to get unemployment checks would seem to me to be a sufficient show of some need for a bit examination of policies in place in the applicable geographic locations. If some tweaking needs to be done, those closer to the problem are likely better able to see what's going on & why.
I didn't mean to make my response this long. :o)