Shinya Kajitani

Occupation, Retirement and Cognitive Functioning

ABSTRACT The purpose of this paper is to examine the causal impact of the duration of retirement on the cognitive functioning of male elderly workers in Japan using data from the National Survey of Japanese Elderly. We explore how the complexity of a workers longest served job affects cognitive functioning after retirement. In particular, we investigate eight dimensions of the longest served job using information listed in the United States Dictionary of Occupational Titles, namely physical demands, mathematical development, reasoning development, language development, the jobs relationship to data, the jobs relationship to people, the jobs relationship to things and the specific vocational preparation required. Our estimator takes account of the potential endogeneity of the duration of retirement and the left-censoring of the duration of retirement. Our empirical evidence suggests that the duration of retirement has a negative and significant impact on cognitive functioning. Moreover, among the eight dimensions of job characteristics, high complexity in the jobs relation to data is found to be an important job characteristic in delaying the deterioration of cognitive functioning after retirement.

Use It Too Much and Lose It? The Effect of Working Hours on Cognitive Ability

Using data from Wave 12 of the Household, Income and Labour Dynamics in Australia (HILDA) Survey, we examine the impact of working hours on the cognitive ability of people living in Australia aged 40 years and older. Three measures of cognitive ability are employed: the Backward Digit Span; the Symbol Digits Modalities; and a 25-item version of the National Adult Reading Test. In order to capture the potential non-linear dependence of cognitive ability on working hours, the model for cognitive ability includes working hours and its square. We deal with the potential endogeneity of the decision of how many hours to work by using the instrumental variable estimation technique. Our findings show that there is a non-linearity in the effect of working hours on cognitive functioning. For working hours up to around 25 hours a week, an increase in working hours has a positive impact on cognitive functioning. However, when working hours exceed 25 hours per week, an increase in working hours has a negative impact on cognition. Interestingly, there is no statistical difference in the effects of working hours on cognitive functioning between men and women.

Japan's Reemployment System and Work Incentives for the Elderly

This paper clarifies the features of the Japanese reemployment system. We examine the impact of this system on employees’ incentive to continue to work for their current firms after mandatory retirement. Using two large microdata sets for Japanese firms and workers, this paper shows that: 1) for the firms with a reemployment system, the steeper the slope of the wage profile until mandatory retirement, the more wages decrease on reemployment, and 2) although a worker’s wage on reemployment decreases, the wage reduction on reemployment does not necessarily make the workers in small/mid-size firms leave their current firm.