I'm sure you'll agree that long term economic numbers should be adjusted for inflation to be more meaningful, whether this is happening in a reasonable way is another question.
The problem is that "adjusting for inflation" makes sense only as a rough and vague heuristic, not as an exact measure of objective value which can be computed up to three, four, or more significant digits. The reality is that when you compare the purchasing power of money in different places and times, the differences in a myriad of relevant factors are often so great that it makes no sense at all to express them with a single number, except perhaps for the purposes of some extremely rough, Fermi problem-style calculation.
The idea that you can define some objective and scientific "price index" and then do calculations that will tell you that some "real" values differ by 4.83%, or invent models that will predict such figures by capturing real insight, is completely detached from reality. This is not a simplification of a problem to make attacking it easier; it's not even an instance of unjustified simplification -- rather, it means dreaming up complete fantasies and giving them a pseudoscientific dressing. I simply see nothing comparable among natural scientists, who are generally capable of dissolving the concepts they work with and avoiding getting lost in such elaborate fantasies built of reified artificial concepts.
(From this it also follows that most discussions of economic growth are nonsense on stilts, since they require combining the nonsensical notions of "real" values with GDP and similar figures, which have their own host of problems that normally go unacknowledged, and which are also usually impossible to discuss rationally.)
The reality is that when you compare the purchasing power of money in different places and times, the differences in a myriad of relevant factors are often so great that it makes no sense at all to express them with a single number
That is too sweeping a criticism. We have to model the world somehow when making decisions, and quantitatively. That goes for policy makers also.
Are you familiar with Jared Diamond's lay account and defense of operationalization, here? I'd be interested to hear what parts of it you object to.
A Wall Street Journal article by Harvard professor of government Harvey Mansfield claims that the social sciences and humanities are inferior to the sciences. The article implicitly urges undergraduates to major in science. From the article:
Do you agree with this? As a game theorist I probably have a rather biased view of the situation. It's certainly true that the ideal of the scientific method is vastly better than the practice of economists, but I think that majoring in economics provides better training for a rationalist than majoring in any of the sciences does.
Economics explicitly considers what it means to be rational. Although it infrequently considers ways in which humans are irrational, I'm under the impression that the hard sciences never do this. Furthermore, because economists can almost never perform replicable experiments we have to rely on what everyone in the profession recognizes as messy data; therefore we’re far more equipped than hard scientists to understand the limits of using statistical inference to draw conclusions from real world situations. Although I have seen no data on this, I bet that a claim by nutritionists that they have found a strong causal link between some X and heart disease would be treated with far more skepticism by the average economist than the average hard scientist.