14. Sometimes it's helpful to graph a problem like this first because it clarifies what we're looking for in a correct answer. Clearly if a firm hires more workers without the wage increasing it must be small relative to the market and so it faces a horizontal labor supply curve (we know this because the question states that the firm hires in a perfectly competitive factor market). So, all we are looking for in a correct answer is something which would lead to an increase in demand for labor, or demand for the output of the firm which would induce the firm to hire more labor.