Along with data about actual, desired and anticipated job characteristics, this paper uses a novel data element, the subjective conditional probability of working at age 70, to estimate the causal effects of job characteristics on retirement in the U.S. Having flexible work hours is the most consistent predictor of retirement preferences and expectations: if all current workers had flexible hours, the fraction working at age 70 would be 0.322, but it would be just 0.172 if none had this option. Job stress, physical and cognitive job demands, the option to telecommute, and commuting times were additional predictors of retirement expectations.