## Facts

- The Secretary of Labor sued Corning Glass Works under the Equal Pay Act (EPA) seeking back pay and injunctive relief for alleged sex-based wage discrimination at plants in New York and Pennsylvania.
- Corning historically staffed inspection jobs by sex: women primarily worked day-shift inspection and men worked night-shift inspection.
- Male night-shift inspectors received a higher base wage than female day-shift inspectors, even though the inspection work was found to require equal skill, effort, and responsibility.
- After unionization, a plant-wide night shift differential was added on top of the existing base-wage gap between male night inspectors and female day inspectors.
- Corning’s night inspection positions had been filled by men transferred from higher-paid male day jobs; those men retained and secured higher wages than women day inspectors.
- In 1966, Corning opened night inspection jobs to women through a seniority-based bidding process as vacancies occurred.
- In 1969, Corning implemented a job evaluation plan setting a single base wage for all newly hired inspectors regardless of sex or shift, but preserved higher “red-circle” rates for pre-1969 employees working nights.
- Lower courts reached conflicting results: a violation was found and affirmed regarding the New York plant, while no violation was found and affirmed regarding the Pennsylvania plant.

## Issues

1. Whether day and night inspection jobs are performed under “similar working conditions” under the EPA, or whether time of day makes the jobs noncomparable.
2. Whether Corning proved the higher base wage for night inspectors was a differential “based on any other factor other than sex,” such as compensation for night work.
3. Whether Corning’s post-1966 and post-1969 changes eliminated any EPA violation, including whether “red-circle” rates continued unlawful pay disparities.

## Decision

- The Court held Corning violated the EPA by paying higher wages to male night inspectors than to female day inspectors for equal work.
- “Working conditions” under the EPA was limited to physical surroundings and hazards, not the time of day worked; therefore, the jobs were performed under similar working conditions.
- Corning did not carry its burden to show the higher base wage resulted from a factor other than sex; the differential was tied to a sex-segregated wage structure.
- Opening night jobs to women did not cure the violation while women day inspectors continued to be paid a lower base wage for equal work.
- The 1969 plan did not end the violation to the extent it preserved higher “red-circle” night rates that perpetuated the prior differential.
- The Court affirmed the judgment finding a violation at the New York plant and reversed the judgment finding no violation at the Pennsylvania plant, remanding for further proceedings.

## Legal Principles

- Under the EPA, “similar working conditions” refers to physical surroundings and hazards, not shift time or time of day.
- Once equal work is shown, the employer bears the burden to prove a wage differential fits within a statutory exception, including a differential based on a factor other than sex.
- A wage structure originating in sex-segregated job assignments cannot be justified merely by labeling the higher wage as a night-work premium without proof it is genuinely and neutrally based.
- An employer does not eliminate an EPA violation by permitting access to higher-paid positions if it continues paying a lower rate for equal work performed by the other sex.
- Pay practices that preserve or carry forward prior sex-based differentials, including “red-circle” rates derived from an earlier discriminatory structure, can constitute a continuing EPA violation.

## Conclusion

The Court ruled that Corning’s higher pay for male night-shift inspectors violated the Equal Pay Act because shift time is not a distinct “working condition” and the company failed to prove the differential rested on a sex-neutral factor; later policy changes did not cure the violation while unequal base pay or preserved legacy differentials remained.


Corning Glass Works v. Brennan, 417 U.S. 188 (1974)