Economics: How much influence does the U.S. administration really have?

[CookingWithGas]

When the economy is strong, the President takes credit. When it's poor, everyone blames the President. Are either of these justifiable?

I am not an economics scholar but I have studied it at the graduate level (albeit nearly 30 years ago). It seems to me that the economy is such a complex thing that economists don't even understand it that well nor is there universal agreement on causes and effects. It doesn't seem reasonable that the economic policy of a given adminstration would have a measurable effect within the tenure of that administration.

Is it possible to measure any economic impact of administration policies when there are so many other variables that they can't control?

(As a tangent, there are also the conspiracy theorists who call upon the government to "do something" when oil prices go up, as though it could repeal the law of suppy and demand. The government has really little influence over it and has not found evidence of illegal price fixing.)

[ultrafilter]

The government certainly has the power to pass laws that create incentives for people to act in a certain way. Beyond that, it's not clear.

[BrainGlutton]

Originally Posted by CookingWithGas

(As a tangent, there are also the conspiracy theorists who call upon the government to "do something" when oil prices go up, as though it could repeal the law of suppy and demand. The government has really little influence over it and has not found evidence of illegal price fixing.)

Not quite true. Oil is a cartelized commodity. The price per barrel is determined by the law of supply and demand, but the supply on the global market is determined by OPEC's production quotas. In fact, one of the necons' aims in invading Iraq was to privatize its state-owned oil industry and, thereby, break the back of OPEC. It didn't work out that way, mainly because the U.S. oil companies, for their own reasons, didn't want it to. See here.