Competitive Labor Markets

A mid-sized city has roughly 300 baristas working at about 25 dollars an hour. Nobody picked that number. No boss decreed it, no council voted on it. It came out of a market — thousands of coffee shops each deciding how many workers to hire, thousands of workers each deciding whether to take a job at the going rate. Where those two sets of decisions meet is the equilibrium wage.

That’s the competitive labor market model: many firms competing to hire, many workers competing for jobs, no one big enough to move the price. Every firm takes the wage as given and hires until its last worker’s MRP equals it.

Two curves do all the work. Market labor demand $L^D(w)$ is the total workers all firms want to hire at wage $w$ — the sum of every firm’s MRP curve, so it slopes DOWN (higher wage → each firm hires fewer). Market labor supply $L^S(w)$ is the total workers willing to take a job at wage $w$ — it slopes UP (higher wage attracts more workers). The market wage $w^{\ast }$ is the one wage at which they’re equal.

Two takeaways. Direction of the shift determines what happens to the wage. Demand-side shocks (more product demand, better technology, higher productivity) push wage and employment in the SAME direction. Supply-side shocks (immigration, training, demographic changes) push wage and employment in OPPOSITE directions. Workers are paid their MRP at equilibrium, so anything that raises MRP — better tools, more popular products, more education — flows directly into higher wages.