William Guthrie managed a JC Penney Company store in Meridian, Mississippi. JC Penney originally had a policy requiring all store managers to retire at age 60, but this policy was changed after passage of the ADEA. In 1979, just before Guthrie’s 60th birthday, various Penney employees made “friendly” inquiries about his retirement plans. Guthrie, however, continued to manage the Meridian store, receiving satisfactory performance ratings and making decent profits for JC Penney. In 1982, however, Guthrie’s new Penney supervisor reprimanded Guthrie before other store employees, overrode several decisions ordinarily made by Guthrie, lowered Guthrie’s performance ratings, and gave him some difficult new performance objectives. Feeling that his discharge was inevitable, Guthrie resigned. Under the younger store manager who succeeded him, the Meridian store did less well in sales and profits, but the new manager received satisfactory performance ratings and was allowed to run the store without interference. Guthrie sued Penney for constructive discharge under the ADEA. What method of proof would his suit involve? Can that method be used under the ADEA?