The “equal pay for equal work” rule is applicable regardless of a job’s title or other identifying feature if the positions are closely related in terms of responsibility, work output, and needed skill and educational level. However, a pay differential may, under certain circumstances, be permissible under the New York Equal Pay Law if it is based upon productivity, a seniority system or a merit system, or another legitimate factor that is not based on a protected characteristic, such as education, training, or prior work experience. Regardless, these exceptions are inapplicable in situations where the employer’s specific policies and practices cause a disparate impact to a protected group of workers, or where an employer refuses to adopt an alternative employment practice that would serve the same business purpose -- yet would avoid pay disparities to a protected class.