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.

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.