Proportionality of Marginal Cost to Wage under Constant Labor Market Competition

A manufacturing firm's cost to produce one additional unit has recently gone up. The firm has confirmed that the nominal wage it pays its workers has remained constant. Based on the formula for marginal cost, $MC = (1+\eta)\frac{W}{\lambda}$, where $W$ is the nominal wage, $\lambda$ is labor productivity, and $\eta$ is a parameter related to labor market competition, which of the following scenarios provides a valid explanation for the increased marginal cost?

Comparative Marginal Cost Analysis

A firm's cost to produce one additional unit is given by the formula $MC = (1+\eta)\frac{W}{\lambda}$. In this formula, $W$ is the nominal wage, $\lambda$ is labor productivity, and $\eta$ is a parameter that increases when it becomes more difficult for the firm to attract new workers. If a local government implements a new policy that makes it easier for this firm to hire workers, the firm's marginal cost will increase, assuming wages and productivity do not change.

A company pays a nominal wage ($W$) of $30 per hour. Its labor productivity ($\lambda$) is 10 units per hour. The parameter reflecting competition in the labor market ($\eta$) is 0.2. Using the formula for the additional cost of producing one more unit, $MC = (1+\eta)\frac{W}{\lambda}$, the company's marginal cost is $____.