For example, in USA interest rates are 1-2% percents, while in Russia it is normal to have up to 8% anually for US dollars account. Same goes for Euro. For Russian ruble it can be up to 12%, but with 10% annual inflation it is the same effectively. Can anyone explain such a difference?
The United States Federal Reserve has decided that interest rates should be low. (They think it may help the economy. The details matter little here though.) It will enforce this low rate by buying Treasury bonds at this very low interest rate. (Bonds are future money, so this means they pay a lot of money up front, for very little interest in the future. The Fed will pay more than anyone who offers less money up front, so they can set the price as long as they're willing to buy.) At the end of the day, Treasury bonds pay nearly no interest.
Since there's little money to be made with Treasuries, people who want better-than-zero returns will bid up the current-price of any other bonds or similar loan-like instruments to get what whatever rate of return that they can. There's really no more than one price for money; you can think of the price of those bonds as basically
I realize thinking about bond prices is weird and different than other prices (you're measuring future-money using present-money and it's easy to be confused) and assure you it ultimately makes sense :)
Anyway. Your savings account money has to compete with everyone else willing to lend money to banks. Everyone-else lends money for peanuts, so you get peanuts on your savings account too. Your banking is probably worth more to your bank on account of your check-card payment processing fees (collected from the merchant) than from the money they make lending out your savings (notice how many places have promotional rates if you make your direct deposits or use your check card to make a purchase N times a month).
In Europe, it's similar, except you've got a different central bank. If Europe's bank operated radically differently for an extended period of time, you'd expect to see a difference in the exchange rates which would ultimately make the returns from investing in those currencies pretty similar as well. Such a change may show up domestically as inflation in the country with the loose-money policy, and internationally as weakness against other currencies. There's really only one price for money around the entire world. Any difference boils down to a difference in (perceived) risk.
The short answer is that banking is complicated, but the bank really doesn't need your money because it can get it from the Fed almost free, it can only use 90% of the money you give the bank, it can only make money on that 90% from very low-risk and thus low-return investments, and as it has to show a profit to its shareholders it will take whatever cut it needs to off the top of the returns. All of these things combine to make savings account interest roughly .05% in the US right now.
The longer answer:
All FDIC-insured banks (which the US requires all "depositor" banks to be) are subject to regulation by the Federal Reserve. The very first rule that all banks must comply with is that depositor money cannot be invested in things the Fed terms "risky". This limits banks from investing your money in things that have high returns, like stocks, commodities and hedges, because along with the high possible returns come high risk. Banks typically can only invest your savings in T-debt and in certain Fed-approved AAA bonds, which have very low risk and so very little return.
The investment of bank assets into risky market funds was a major contributor to the financial crisis; with the repeal of the Glass-Steagall Act, banks had been allowed to integrate their FDIC-insured depositor business with their "investment banking" business (not FDIC insured). While still not allowed to bet on "risky" investments with deposits, banks were using their own money (retained profits, corporate equity/bond money) to bet heavily in the markets, and were investing depositor funds in faulty AAA-rated investment objects like CDOs. When the housing market crashed, banks had to pull out of the investment market and cash in hedges like credit-default swaps to cover the depositor losses, which sent a tidal wave through the rest of the market.
Banks really can't even loan your money out to people who walk in, like you'd think they would and which they traditionally used to do; that's how the savings and loan crisis happened, when speculators took out huge loans to invest, lost the cash, declared bankruptcy and left the S&Ls (and ultimately the FDIC) on the hook for depositors' money.
So, the upshot of all this is that the bank simply won't give you more on your money than it is allowed to make on it.
In addition, there are several tools that the Fed has to regulate economic activity, and three big ones play a part. First is the "Federal Funds Rate"; this is the interest rate that the Fed charges on loans made to other banks (which is a primary source of day-to-day liquidity for these banks). Money paid as interest to the Fed is effectively removed from the economy and is a way to reduce the money supply. Right now the FFR is .25% (that's one quarter of one percent) which is effectively zero; borrow a billion dollars ($1,000,000,000) from the Fed for one month and you'll pay them a scant $208,333. Banks lend to other banks at a rate based on the FFR, called the Prime Rate (usually adding some fraction of a percent so the lending bank makes money on the loan). This means that the banks can get money from the Fed and from other banks very cheaply, which means they don't have to offer high interest rates on savings to entice individual depositors to save their money with the bank.
Second is "quantitative easing", which just means the Fed buys government bonds and pays for them with "new" money. This happens all the time; remember those interest charges on bank loans? To keep the money supply stable, the Fed must buy T-debt in the amount of the interest being charged, otherwise the money leaves the economy and is not available to circulate. The Fed usually buys a little more than it collects in order to gradually increase the money supply, which allows the economy to grow while controlling inflation (having "too much money" and so making money worth less than what it can buy).
What's new is that the Fed is increasing the money supply by a very large amount, by buying bonds far in excess of the (low) rates it's charging, and at fixed prices determined by the yield the Fed wants to induce in the markets. In the first place, with the Fed buying so many, there are fewer for institutions and other investors to buy. This increases the demand, driving down yields as investors besides the Fed are willing to pay a similar price, and remember that T-debt is one of the main things banks are allowed to invest your deposits in. Inflation isn't a concern right now despite the large amount of new money being injected, because the current economy is so lackluster right now that the new cash is just being sat upon by corporations and being used by consumers to pay down debt, instead of what the Fed and Government want us to do (hire, update equipment, buy houses and American cars, etc). In addition, the "spot market price" for a T-bond, or any investment security, is generally what the last guy paid. By buying Treasury debt gradually at a fixed price, the Fed can smooth out "jitters" in the spot price that speculators may try to induce by making low "buy offers" on T-debt to increase yields.
Lastly, the Fed can tell banks that they must keep a certain amount of their deposits in "reserve", basically by keeping them in a combination of cash in the vault, and in accounts with the Fed itself. This has a dual purpose; higher reserve rates allow a bank to weather a "run" (more people than usual wanting their money) and thus reduces risk of failure. An increased reserves amount also reduces the amount of money circulating in the economy, because obviously if the banks have to keep a percentage of assets in cash, they can't invest that cash. Banks are currently required to keep 10% of "deposited assets" (the sum of all checking and savings accounts, but not CDs) in cash. This compounds the other problems with banks' investing; not only are they not getting a great return on your savings, they can only use 90% of your savings to get it.
Typically developing economics are marked by moderate to high inflation [as they are growing at a faster pace], higher in savings rate and higher lending rates. If you reduce the lending rate, more business / start-up will borrow at cheaper rate, this in turn means lowers savings rate and leads to higher inflation. To combat this Central Banks make borrowing expensive, which lowers inflation and increases the saving rate. Essentially all these 3 are tied up.
As to why these countries offer higher interest on USD is because most of the developing countries have trade [current account] deficit. They need to bring in more USD in the country. One of the ways is to encourage Non Resident Citizens to park their foreign earning back home, ensuring more funds USD inflow.
The rate differential also acts as a guide as to how the currency would be valued against USD. For example if you get 8% on USD, less than 12% had you converted same to Rouble, at the end of say 3 years, the exchange rate between USD and Rouble would factor that 4%, ie rouble will go down.
Developed countries on the other hand are marked by low inflation [they have already achieved everything] as there is no spurt in growth, it more BAU. They are also characterized by low savings and lending rates.
The 8% rate offered by Russian banks on US Dollar accounts reflects the financial problems they have. They would prefer to lend US Dollars on the international financial markets at the same rate as US banks, but loans to Russian banks are considered to be more risky. In fact, the estimated "default" risk is ~6%.
Your ruble deposits at Russian banks are most likely backed by state guarantees, which reduces the risk and therefore the effective interest rate.
There is really much simpler explanation for the interest rate differences in different countries. It is the interest rate arbitrage. It is a very well explored economic concept, so you can look it up on the Internet, in case you want to know more.
1) Interest rates for the same currency in different countries Basically, as one smart person here pointed out, there is only one price of money in free market economy. It happens, because investors can move their money unrestrictedly anywhere in the World to capitalize on the local interest rates advantage. For instance, if I can take a loan in the USA at 3-4% annual interest and receive 5-6% annual income on my dollar deposit in Russia, I would take a loan in the US and open a deposit in Russia to enjoy a risk free interest rate differential income of 2% (5-6% - 3-4% ~ 2%). So, would any reasonable person. However, in real World very few banks in Russia or anywhere would pay you an an interest rate higher than it can borrow money at. It'd probably lose money if it'd do so. Anyways, the difference between the risk free rate and interest rate on the dollar deposit can be attributed to the risk premium of this particular bank. The higher expected return, the greater risk premium.
If there is a positive difference in the interest rates on the dollar deposits in different countries, it will almost entirely accounted for the risk premium. It is generally much riskier to keep money in, say Russian bank, than American. That's why investors want greater return on their dollar deposits in Russian banks than in American. Of course, if you'd want to park your USD in Russian bank you'd also have to consider transaction costs. So, as you may have already guessed, there is no free lunch.
2) Interest rates in different currencies for different countries If we are talking about the interest rates in different sovereign currencies, it is a somewhat similar concept, only there is more risk if you keep money in local currency (risk premium is much higher). Probably, the biggest component of this risk is inflation (that is only attributed to the prices in local currency). For that reason, current interest rates on deposits in Russian Rubles are at 10-12%, but only 1-3% in the US Dollars. An economic concept that discusses this phenomenon in great detail is Interest Rate Parity.
Hope this was helpful.
P.S. It doesn't look quite realistic that you can get an 8% annual income for USD deposit in Russia with the interest rates in the U.S. being at 1-2%. At present moment, a 30-year mortgage annual interest rate in the US is at ~2-3% and an annual interest rates for dollar deposits in Sberbank (one of the safest Russian banks = very little risk premium) is at 1-3%. So, arbitrage is impossible.
Banks in general will keep saving rates as low as possible especially if there is a surplus of funds or alternative access for funding as in the case of the FED in the USA.
So generally speaking why would bank pay you a high interest rate when they cannot generate any income from your money. Usually we will expect to see a drop in the loan interest rate when their is a surplus of funds so as to encourage investment. But if the market is volatile then no banks will allow easy access to money through loan. The old traditional policy of lending money without proper security and no control from the central bank has created serious problems for savings account holders when some of these banks went into bankruptcy. It is for this reason most countries has modified their Financial Act to offer more protection to account holders. At the moment banks must follow rigid guidelines before a loan can be approved to a customer.
In my country (Guyana) we have seen the collapsed of a few banks which send a shock wave across the county for those that have savings held at those bank. We have also seen unsecured loans having to be written off thus putting serious pressure of those banks. So government step in a few years ago and amend the act to make it mandatory to have commercial banks follow certain stick guidelines before approving a loan.