According to this blog article:
http://johnsville.blogspot.com/2011/06/modern-monetary-theory-mmt-in-nutshell.html...
There is really not that much "theory" in Modern Monetary Theory. MMT is more concerned with explaining the operational realities of modern fiat money. It is the financial X's and O's, the ledger or playbook, of how a sovereign government's fiscal policies and financial relationships drive an economy. It clarifies the options and outcomes that policy makers face when they are running a tax-driven money monopoly. Proponents of MMT say that its greatest strength is that it is apolitical.
The lifeblood of MMT doctrine is a government's fiscal policy (taxing and spending). Taxes are only needed to regulate consumer demand and control inflation, not for revenue. A sovereign government that issues its own floating rate fiat currency is not revenue constrained. In other words, taxes are not needed to fund the government. This point is graphically described by Warren Mosler as follows:
"what happens if you were to go to your local IRS office to pay with actual cash? First, you would hand over your pile of currency to the person on duty as payment. Next, he'd count it, give you a receipt and, hopefully, a thank you for helping to pay for social security, interest on the national debt, and the Iraq war. Then, after you, the tax payer, left the room he'd take that hard-earned cash you just forked over and throw it in a shredder.
Yes, it gets thrown it away . Destroyed!"
— The 7 Deadly Frauds of Economic Policy, page 14, Warren Mosler
Gadzooks!
The delinking of tax revenue from the budget is a critical element that allows MMT to go off the "balanced budget" reservation. In a fiat money world, a sovereign government's budget should never be confused with a household budget, or a state budget. Households and U.S. states must live within their means and their budgets must ultimately be balanced. A sovereign government with its own fiat money can never go broke. There is no solvency risk and the United States, for example, will never run out of money. The monopoly power to print money makes all the difference, as long as it is used wisely.
MMT also asserts that the federal government should net spend, again usually in deficit, to the point where it meets the aggregate savings desire of its population. This is because government budget deficits add to savings. This is a straightforward accounting identity in MMT, not a theory. Warren Mosler put it this way:
"So here's how it really works, and it could not be simpler: Any $U.S. government deficit exactly EQUALS the total net increase in the holdings ($U.S. financial assets) of the rest of us - businesses and households, residents and non-residents - what is called the "non-government" sector. In other words, government deficits equal increased "monetary savings" for the rest of us, to the penny. Simply put, government deficits ADD to our savings (to the penny)."
— The 7 Deadly Frauds of Economic Policy, page 42, Warren Mosler
Therefore, Treasury bonds, bills and notes are not needed to support fiscal policy (pay for government). The U.S. government bond market is just a relic of the pre-1971 gold standard days. Treasury securities are primarily used by the Fed to regulate interest rates. Mosler simply calls U.S. Treasury securities a "savings account" at the Federal Reserve.
In the U.S., MMTers see the contentious issue of a mounting national debt and continuing budget deficits as a pseudo-problem, or an "accounting mirage." The quaint notion of the need for a balanced budget is another ancient relic from the old gold standard days, when the supply of money was actually limited. In fact, under MMT, running a federal budget surplus is usually a bad thing and will often lead to a recession.
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