While I agree with you in general I must say that I think your view of the 20th century is a bit too dystopian. Humanity has improved in the last one hundred years, and measurably so.
Beyond that, surely child mortality, literacy, and poverty are enough to prove your point, GDP doesn't really even fit!
How about the fraction of disposable personal income spent on food?
http://www.ers.usda.gov/briefing/cpifoodandexpenditures/data...
From 1929 to the present that has dropped from 23.4% to 9.5%. This despite what other evidence suggests is a considerable increase in the quantity and overall quality of said food. For instance today we eat far more meat per capita than people did 80 years ago, and meat is rather expensive.
> This despite what other evidence suggests is a considerable
> increase in the quantity and overall quality of said food
Currently -- iirc -- most fertilizers come from livestock feces. My personal views on whether or not we should be 'farming living beings' notwithstanding... You have to feed those livestock something in order for them to produce feces. The current practice is to grow food for them (or to feed them the ground out remains of other livestock animals). So you need to grow more food in order grow more food? That doesn't seem sustainable.
This is not even getting to the issues we have with fertilizers running off into waterways and creating 'dead zones.'
2. The growth of 'comfort' or 'junk' foods I see as more of a regression than anything else. Their existence would be fine, if it weren't that some people don't know the meaning of moderation...
You have chosen to compare what I was talking about, GDP (Nominal in this case) and a percentage of dollars (since you quote the USDA, I was talking about worldwide btw, just like the op) to food. It's an apples to oranges comparison, and for the most part, reinforces my comment above, that someone down-voted.
Yes, we spend less on food than we did in 1929. Do you have cows in your back yard btilly? Probably not. Why do I ask? Because comparing the farming industry in 1929 to the industry of 2010 is like comparing the age of slaughtering your own "home-raised" cow, to the age of mechanized cow raising, slaughtering, and delivery into the closest super market. Um, of course the price is lower. The real interesting part, though, is that the price could be even lower if the money supply wasn't artificially increased by trillions of dollars. Fun fact, if $1.00 would have purchased $1.00 worth of goods in 1929 (which it did), if you had instead, saved it until 2010, it would purchase ... wait for it ... $0.08 worth of goods. Does that not strike you as odd, that although productivity has boomed, e.g., we can make more things for less dollars, the value of the dollar has plummeted?
But to the main point, it shows by your argument that you failed to grasp the full extent of what I was saying. Money is just paper. How do I know that? When a country can lend itself (by selling its paper for another countries paper, in the case of the US, China purchases the vast majority of US treasuries, though, no one even knows if China is printing money, or being disciplined with their monetary policy) trillions of dollars and put that into circulation, of course the GDP will rise, but has progress been made? NO. GDP is nominal, not absolute, and it does not reflect productivity, or even actual PHYSICAL output! It reflects prices.
In a small country of 10 people, if all of those people have $1, and a barrel of oil is $1, the GDP is $10 or 10 barrels of oil. If the government prints up $10 more dollars and hands it out to those 10 people, now everyone has $20, but oil prices increase to $20 since MV = PQ. Ah, now the GDP is $20, but we can still only buy 10 barrels of oil. Now that is Your kind of progress.
My point, to wrap it up, was that things like global literacy and hunger are things we have been improving. Improving global GDP has no measurable impact by just inflating the number. The number is just a number unless it is put in real terms, which is not how the original post read when it listed "improving global GDP" as some kind of accomplishment.
Before you asked for a real currency, backed by something. With the implicit point that you don't believe the numbers.
Well my point is that any basket of goods implicitly defines a currency. Therefore food defines a currency, which is backed by the very real effort and resources it takes to produce that food. I've shown that GDP per capita in that "currency" has gone up. I presented figures for the USA because that is what I found first, but the same is true for the world as a whole. This is true at the same time that the number of people has gone up. Which means that food production must have gone up a lot.
You demanded a real measuring stick. I gave one. There is nothing special about that measuring stick. You can adjust for inflation using the CPI. You can adjust by many specific things we use daily, such as the cost of energy or metal. GDP has gone up.
Now you say that it is an apples and oranges comparison? Well of course it is! Productivity increases because we do things more efficiently. Using 1920s methods and technology we can't be any more productive today than we were 80 years ago. But we're using 2010 methods and technology, and there is a stark difference. The result is that today we generate more stuff, services, and things people want than at any point in history.
So yes, you are trivially right that inflation makes GDP numbers meaningless in isolation. But those numbers don't exist in isolation. We have lots of ways to adjust for inflation. After you have done so, it is clear that you can quibble about specific numbers but the broad point is good. Productivity has gone up.
No one offered up inflation adjusted GDP, and my point, which was very simple, though long winded, was that you simply can't say "Increases in GDP make the world better".
Look at zimbabwe. Their GDP is Hundreds of Trillions of Zimbabwe dollars, because they print a 1 Trillion dollar note.
To be more fair, the OP would have been better off using your food example instead of saying "GDP rose". I wasn't arguing that we are worse off today than 1929, just that it isn't because of an increase in GDP. If the currency wasn't inflated, we could get better off with GDP staying constant, through productivity gains.