Say the average increase in pay for non-union workers in 2011 is 2% across the u. s. if a workers' union successfully negotiates a 3 year collective agreement that provides a 4.5% raise in 2011, and a 4.3% raise in 2013, then the for-profit employer will typically

cut back the expansion of labor as a trade off between higher salaries but fewer workers.

Explanation:

If the employer believes that he is paying above average wages, he will try to reduce labor costs. Since unions are specially good in preventing massive layoffs, the other alternative left for the employer is to not hire new employees, or reduce the number of new employees that he expected to hire.