Why Tightening Mortgages Causes Personal Loans to Surge — The Balloon Effect Explained

In July, banks tightened mortgage lending limits and raised rates — and something unexpected happened. Mortgage lending fell, but personal (credit) loans surged by over 2.4 trillion won. Household lending blew past the government's 1.5% growth target. This is the 'balloon effect' in action.

What is the balloon effect?

Squeeze one side of a balloon and the other side bulges out. Loan regulations work the same way. When the government tightens mortgages, people who need money simply find other channels — personal loans, lease deposit loans, credit card loans. Total household debt doesn't shrink; it just changes shape.

Why does this keep happening?

Think from the borrower's perspective. Someone needs money to buy a home, cover a lease deposit, or fund a business. When mortgages get cut off, the need doesn't disappear — people just find a different route. Regulations tend to redirect demand, not eliminate it.

Does the balloon effect happen in stock markets too?

Yes, the same principle applies. When domestic stock market regulations tighten, money flows to foreign markets (hence the surge in Korean investors buying U.S. stocks). When certain crypto exchanges get shut down, trading moves to other coins or decentralized platforms. 'Squeeze one channel and money flows somewhere else' — that's just how money works.

So are loan regulations useless?

Not at all. Regulations can effectively cool overheated segments of a market. But to actually reduce total household debt, a single regulation isn't enough — it requires income growth, higher interest rates, expanded housing supply, and more, working together. Plug one hole and leave others open, and the water just flows elsewhere.

When a policy produces unintended consequences instead of its intended effect, economists sometimes call it the 'cobra effect' — named after a story from British colonial India, where offering bounties for dead cobras led people to breed cobras and cash in. The balloon effect in loan regulation is cut from the same cloth.