Interest rates: what they are and how they move the economy

The price of money

Everything has a price — money included. When you take out a loan, the price you pay to use someone else’s money is the interest rate; when you’re the one lending — to a bank via a deposit, to a state via a bond — the rate is what you collect. It’s expressed as a yearly percentage: at 5%, borrow 1,000 and you owe 1,050 a year later.

Understand this and you’ve understood half the economics in the headlines. The other half is understanding who moves this price.

Who decides: the ECB and its three rates

In the euro area, benchmark rates are set by the European Central Bank. There are three: the deposit facility rate (today the one that matters most), the main refinancing rate and the marginal lending rate. As of mid-2026 they stand at 2.25%, 2.40% and 2.65% respectively (ECB).

None of us deposits money at the ECB, so these numbers don’t touch you directly. But a transmission chain starts there and runs straight to your bank account: official rates steer Euribor (the rate banks charge each other), Euribor moves variable mortgages, and the overall level of rates shapes personal loans, savings accounts and government bonds.

Practical example: you pay 500 a month on a variable mortgage and the ECB hikes by half a point. Within months Euribor adjusts, and your monthly payment can rise noticeably. Nobody touched your contract: the price of money moved upstream.

The lever that steers the economy

Why does the ECB move rates at all? Because they’re its main lever for keeping inflation near 2%. The mechanism is intuitive. Pricier money means heavier mortgages and loans: households postpone purchases, firms delay investments, demand cools and prices slow down. Cheaper money does the exact opposite, and is used to revive a stalled economy or climb out of a recession.

One detail most commentary misses: the lever works with a lag of months. A hike decided today cools next year’s prices. Central bankers drive like someone steering a heavy truck — braking well before the curve.

Fixed or variable: the choice everyone eventually faces

On a mortgage, rates become personal.

	Fixed rate	Variable rate
The payment	Identical for the whole term	Tracks the index, up and down
Starting cost	Usually higher	Usually lower
The risk	No surprises	Costlier payments if rates rise
Suits	Those who want certainty	Those who tolerate swings

There’s no universally right answer — only the right one for your situation, which deserves a professional’s advice. This is education, not financial advice.

Compound interest: the quiet force

One last concept, perhaps the most powerful: compound interest. If earned interest stays invested, next year it earns interest of its own. At first the difference is invisible; over twenty years the gap becomes enormous. It works for you when you save and reinvest, and against you when a debt compounds unpaid.

Einstein almost certainly never called it “the eighth wonder of the world” — that quote circulates without a credible source — but the idea would deserve the title anyway. And the fact that a country’s GDP compounds year after year is precisely why a few extra decimals of growth, stacked over decades, add up to enormous gaps between countries.