Why do companies exist at all?

If markets are so efficient, why doesn't everyone just work as a solo freelancer, buying and selling each task on the open market? In 1937 economist Ronald Coase asked exactly this — and won a Nobel Prize partly for the answer. His insight: using the market isn't free. Every trade carries hidden transaction costs — finding the right supplier, negotiating a price, writing and enforcing a contract, checking the work. These frictions are real, even when the good itself is cheap.

A firm exists because it lets you skip those costs. Instead of negotiating a fresh contract every time you need a task done, you hire an employee once and simply direct them. Inside the company, work is coordinated by management, not by haggling. Coase argued this is why companies form at all: they replace a swarm of tiny market transactions with a single ongoing relationship.

This also explains a firm's size and boundary. A company grows by pulling activities in-house until the cost of organizing one more task internally rises to equal the cost of just buying it on the market. That tipping point is the famous "make vs. buy" decision — whether to build a part yourself or purchase it from a supplier. When markets get cheaper to use (think online marketplaces and gig platforms lowering search and contracting costs), the logic tips back toward buying, and firms tend to shrink or outsource.