Effet sur l'Équilibre: Déplacement de l'Offre de Travail

When labor supply increases, the supply curve shifts rightward, meaning more workers are willing to work at any given wage. This creates a surplus of labor at the current wage rate. Employers respond by offering lower wages since many workers are available. The new equilibrium occurs at a lower wage with more workers employed.

Immigration increases the labor supply by expanding the pool of available workers. This shifts the labor supply curve rightward, increasing the quantity of labor available at each wage level. The resulting surplus of labor drives down equilibrium wages. However, employers can now hire more workers at lower wages, increasing overall employment levels in the market.

A leftward shift in labor supply occurs when fewer workers are available at each wage level, often due to demographic changes like declining birth rates. This creates a labor shortage at the existing wage, forcing firms to offer higher wages to retain workers. As wages rise, firms reduce production and hire fewer workers, decreasing overall employment despite higher individual wages.

When labor supply increases and wages fall, it becomes more profitable for firms to expand production by hiring additional workers. Lower wage costs reduce labor expenses, allowing firms to maintain or increase output profitably. The competitive profit maximizing firm responds to lower input costs by increasing quantity demanded, resulting in higher total employment at the new equilibrium.

A labor supply shift changes the quantity of workers available at each wage, while a labor demand shift changes the quantity employers want to hire. Both affect equilibrium wage and employment, but in opposite directions. Understanding both shifts is essential for analyzing how labor markets respond to different economic changes and policy interventions.

The new equilibrium point is determined by the intersection of the shifted labor supply curve with the unchanged labor demand curve. This intersection establishes both the new equilibrium wage and the new quantity of labor employed. In a perfectly competitive labor market, this point reflects where the quantity of labor supplied equals the quantity demanded at the prevailing wage.

When labor supply increases, more workers are willing to accept employment at the current wage, creating excess supply. Employers can fill positions at lower wages without losing workers to competitors. This wage reduction continues until a new equilibrium is reached where the quantity of labor supplied equals quantity demanded, balancing the expanded labor pool with employer demand.