Typically, employers compete with each other in the labor market to get and to retain the best possible workers. Explain how such competition might prevent the unemployment rate from ever being close to zero

What will be an ideal response?

When the unemployment rate is low, employers will offer a relatively high wage to attract high-quality job applicants and to counter poaching of their high-quality employees. Since the cost of labor is high, employers will create as few jobs as possible. The high wage, as intended, will attract a fair number of job seekers, many of whom will remain unemployed.