This may be economics 101, just wanting to check my facts on the phenomenon...
Does inflation, in case of dollars for example, simply come from the fact that the government introduces more money into the system, which causes the value of existing dollar? Or are there other factors in play?
How about banks creating money out of thin air, does it have any role in inflation? (As I understand it, they invent money that they loan to customers, expecting an interest - correct me if I'm wrong!)
The "Austrian" school of economics would say that the definition of inflation is an increase in the supply of money and credit, the result is a general rise in the price level. Mainstream economics teaches that inflation IS a rise in the price level, and usually mentions the silly "phillips" model which claims that inflation occurs due to economic growth (even though graphs of inflation vs nominal gpd growth show no correlation whatsoever).
Let me prove the austrians by introducing you to simple math equation governing money and goods/services: Its called the Quantitative Theory of Money:
M * V = P * Q
Where M is the amount of issued currency in the economy
V is the "velocity" of money (how many times the average dollar changes hands in transactions for good/services over a period of time)
P is the average price of a good or service in the economy
Q is the quantity of goods/services
When you think about it, the supply of money (M), multiplied the number of times the money changes hands (V) represents all the economic activity for the year. Also, the Prices of everything traded, multiplied by the number of those things traded should equal M * V.
So, any increase of P is, by definition a rise in the overall price level.
Now what causes a rise in P over the long run? In the long run Velocity is just a constant, because money can't habitually change hands faster and faster and faster (or slower slower and slower) over long periods of time (not in a normally functioning economy anyway). So you might as well consider V a constant over longer periods of time.
Now, if Q (Quantity of Goods sold) stays the same from one year to another because of a lack of economic growth, the whole rise in the price level is must be caused by and increase in Money Suppy (M).
Interestingly as an economy Grows (Q gets bigger), were there to be no change in the supply of Money (M), Prices would HAVE to decline.
Thus, when the general price level rise, that is and indication of the size of the Money supply increase, net of real economic growth. So if the economy is said to grow 2% in a year, and price inflation was 3%, it meas that money probably grew about 5%.
Now just to introduce another concept M or money supply also includes fractional credit. This is the phenomenon created by the banking system, which will take a deposit of $100 dollars of currency, then lend say $95 to a borrower, who in term buys something from some one who goes ahead and deposits the money somewhere else. A portion of the redeposited $95 then gets lent out AGAIN and thus the same currency starts occupying many places.
This is why all the money that The Federal Reserve has been aggressively printing as part of "quantitative easing" has not cause a big jump in prices (yet). During this time banks have been collapsing their loan portfolios (both due to loan losses, and poor economic prospects reducing lending). If and when lending starts expanding we will see much sharper inflation if the Fed doesn't quickly raise interest rates and collapse the amount of currency its issued.
Its a lot to understand, hope this helps.