Your example of the chipped arrowhead is not very different from economics, which had traditionally relied on observation, until the ability to properly collect and use data arrived.

Micro-economics when it overlaps things like game theory is also a science. There are experiments conducted, and data is used to predict what will happen in similar situations.

The same processes are used in macroeconomics.  (Game theory is also used in macroeconomics.)  Models of behavior are built, and they're used to predict outcomes.  They're then compared with similar situations.

Macro-economics might be an observational science if it was possible to determine which factors in society caused which economic result. But under present conditions saying that a specific tax policy caused a certain type of economic activity is reaching beyond what the data yields.

This, again, is done quite often.  You're working with the assumption that microeconomics and macroeconomics are two easily-separated fields.  They're not.  Macroeconomics is built upon microeconomics.  It always has been.  We know how factors, such as interest rates, affect firms, and can, therefore, estimate the impact of changes in policy.

The parallel between religion, astrology, and economics is that political leaders used the advice and/or justifications from the practitioners of these disciplines to justify their political choices. In all cases an appeal to an unverifiable outside cause is used as "proof".

And, again, you haven't addressed the issue of evidence.  There is no evidence to support the existence of a god.  There is evidence to support economic theories.  What you're essentially saying is that economics provides an avenue for politicians to misuse theories for their own political gain, as they do with religion, but this is no different from any other field.  The same thing happens in the hard sciences on issues like global warming.  Does this disqualify climatology?  Of course not.  But, for some reason, you seem to believe that it disqualifies economics.

I already provided an example of being able to verify the false nature of current Republican claims about Supply-Side economic policy.

If you can't do an experiment, or repetitive observations of similar conditions, it's not science. There are no soft sciences.

You can observe similar conditions repeatedly in economics.  I, again, refer you to my above comment.  By "soft vs. hard sciences," I'm refering to the confidence levels different fields use.

You will find that if you read Galbraith, for example, that he also has a low opinion of the pronouncements of those who prostitute themselves to the political powers.

Speaking of media whores!  I'm not aware of Galbraith having ever contributed anything of long-lasting value to the field of economics.  Galbraith wrote political books.  Period.  The poor guy never got his shot at being the next John Maynard Keynes, because he was never capable of thinking on the same level.

As I said above, we should switch from the pointless debates of economic theories, to the observational data as to whether political policies are working for the greater good. If you have problems with defining the "greater good" read someone like John Rawls.

You can't develop an understanding of whether the "greater good" is being served without an understanding of the economics behind the issues, and the understanding of those economic issues comes from the testing of economic theories against data.  You, therefore, cannot even begin to address issues pertaining to the "greater good" through policy without theories that explain the data well, enable you to bring up options, and choose a policy.

I read Rawls when I was working on my political science degree.  I didn't find his arguments to be at all strong.  But when it comes to political philosophy, there is Locke, Hobbes and Rousseau, and then there is everyone else, in my opinion.

Conservatives want live babies so they can raise them to be dead soldiers. - George Carlin