You're just perpetuating the built in flaws with the system. Just because economists say something is correct it doesn't mean it to be true.
There are very steady economic principles involved in the prime mortage default swaps also, but I doubt anyone would agree that it is now okay, to package mortages now give them a AAA bond rating insure them and watch them explode.
I think you fail to see the big problem here, and I won't call you an idiot, because you are a good student, or at least a good parrot. The big problem is that everything is overvalued and everyone is overconsuming because of it is. The idea that money is worth stuff, and as long as you have money you can buy whatever stuff that money will buy you, makes sense. But what if money is worth the number on it? Because it's not. As for circular flow, I fail to see the relevance. that's just people work for a check and pay taxes, and those taxes supply services. Not complicated at all. hmm.... there is so much to say here but i'm not sure how.
Ok rant over... Let's take the stock market, the commodity market works the same except with slightly more price regulation. So if I buy a share of let's say headbook(hypothetical). Headbook is a company that is superior to facebook in everyway except 0 ads and 0 revenue. I buy it for 20 cents with 100000 shares outstanding the corp is worth 2000 bucks. They have 1 server worth 2g's and that is their only asset. I succefully bought 1% of their realizable value. Now someone wants in and buys my share for 24 cents. The company is now worth 2400$ with only 2000$ dollars of assets. This can continue endlessly until the company is worth a million dollars. It doesn't change the intrinsic value of the company but the market value will continue to change. Eventually people will find themselves stupid and the price will plummet and drop to nothing as the company goes bankrupt.
So now I have an argument base for actual commodities, things we use. The corn we make and eat, and use for random things, is not immune to this. This price gets manipulated continously as oil lobbyists want this price high, farmers want their corn to sell higher, so they manipulate the supply to control prices. As corn escalates in value what really happens? You then create an imaginary value for corn. Eventually the supply of corn regualtes and the price of corn drops, many farmers lose their farms. This has happened THOUSANDS of times! But the investors in the commidity markets only keep their investments for one season, or one season of product. So why are other goods any different? What is the value of a Nike shoe? try to legimitimize the ciruclar flow for Nike. Shoe is worth 8 cents of material, but sells for 60-300$. If that exchange of recources is not standard with everything. Eventually people are going to realize that Nike shoes aren't worth that much and people will stop buying them. So Nike's price will drop then? But that also means they stole how many billions of value to consumers? The value they supply to people is maybe 2 bucks but they make 60$. This is a consumer bubble. Their are millions of consumer bubbles. These won't cause any stress on the economy though. What will cause stress on the economy is... yup back to the stock market, when Nike's market value drops from I don't know 50 billion maybe down to 50/30= 16.67Billion dollars. Now if that happens to Apple, Microsoft, Grangers, Walmart, Samsung, Toyota, General Motors, Honda, many others all in the same year what happens? Instantly there is Trillions of dollars less in the global economy.
What would cause such a thing to happen? Stagnation in buyers. What will cause that to happen, less buying power by the general public. What is happening now? As the quanity of dollars is being forced up the system is stagnating the largest buying force in the world. BUBBLES WILL BURST!! it is there. When credit and imaginary value are allowed to continue these actions will happen.
As for debt never has to be paid. This is so easy to debunk. All you have to do is use a controlled environment. A society of 10 people where one does the farming, for all 10. One person asked if he can get twice the food, and he will give the farmer a shed. This happens every year. How long will it take the builder to chop the head off of the guy who owes him years of food?
Now whatabout a monetary society? Well what if those 10 people had 1 million dollars, that they traded for goods, this way the farmer could instead pay for those additions on his house instead. Well what if someone decided to print out an extra million dollars, now there is 2mil. All money is worth half the price because their is more money in the system. It won't really make a difference right?
The answer is no, but what if the farmer asks for the addition but doesn't have the money to pay for it? The builder agrees and asks him to pay it later. The other 8 people will assume that their is the same amount of money in the system, despite there is now also debt. So more value in society and more debt. As that debt becomes bad debt, the builders prices will raise and deflate the dollar. If you spend 30T dollars those owed money will increase prices and deflate the buying power of the dollar.
So umm... PK is wrong, Ceebass you're wrong. The whole ____ system is wrong. Peel apart every lesson you've learned. If something is not creating value where there was none they are not improving society. You are wrong on real GDP it just makes exchanges immune to price fluctuation. It still accounts for many things that don't have a real wealth generating impact on society, such as service occupation.