Based on a randomized controlled trial applied to employees of a manufacturing company, this study examines the extent to which a corporate sleep program improves workers' sleep health and productivity. In the three-month sleep improvement program, applicants were randomly divided into a treatment group and a control group, and the treatment group was provided with a noncontact sensing device to visualize their sleep. A smartphone app linked to the device notified them of their sleep data every morning and presented them with advice on behavioral changes to improve their sleep on a weekly basis. The results of the analysis revealed the following. First, even after controlling for factors that may cause sleep disturbances and nocturnal awakenings, such as increased workload and the number of days spent working from home during the measurement period, the treatment group showed improved sleep after the program compared to the control group. Second, the treatment group showed statistically significant improvement in presenteeism (productivity). The effect size on presenteeism through sleep improvement was similar regardless of the estimation method used (i.e., ANCOVA estimator of ATT and two 2SLS methods were performed). In particular, we confirmed that productivity was restored through sleep improvement for the participants who diligently engaged in the program. These results suggest that promoting sleep health using information technology can improve sleep deficiency and restore productivity.

The coronavirus disease 2019 (COVID-19) pandemic has impacted the world economy in various ways. In particular, the drastic shift to telework has dramatically changed how people work. Whether the new style of working from home (WFH) will remain in our society highly depends on its effects on workers’ productivity. However, to the best of our knowledge, the effects of WFH on productivity are still unclear. By leveraging unique surveys conducted at four manufacturing firms in Japan, we assess within-company productivity differences between those who work from home and those who do not, along with identifying possible factors of productivity changes due to WFH. Our main findings are as follows. First, after ruling out the time-invariant component of individual productivity and separate trends specific to employee attributes, we find that workers who worked from home experienced productivity declines more than those who did not. Second, our analysis shows that poor WFH setups and communication difficulties are the major reasons for productivity losses. Third, we find that the mental health of workers who work from home is better than that of workers who are unable to work from home. Our result suggests that if appropriate investments in upgrading WFH setups and facilitating communication can be made, WFH may improve productivity by improving employees’ health and well-being.

Although the prior literature has examined the relationship between work schedule characteristics and worker mental health, establishing the causal effect of work schedule characteristics is challenging because of endogeneity issues. This paper investigates how various work schedule characteristics affect workers' mental health using employee surveys and actual working hours recorded over seventeen months in a Japanese manufacturing company. Our sample includes 1334 white-collar workers and 786 blue-collar workers observed from 2015 to 2016. Our major findings are as follows: long working hours cause the mental health of white-collar workers to deteriorate even after controlling for individual fixed effects. Furthermore, working on weekends is associated with mental ill health-the negative effect of an hour increase in weekend work is one and a half to two times larger than that of weekday overtime work for white-collar workers. On the other hand, short rest periods are not associated with mental health for them. Our results indicate that taking a relatively long rest period on weekends is more important for keeping white-collar workers healthy than ensuring a sufficient daily rest period. Regarding blue-collar workers, our analysis reveals that working after midnight is associated with mental ill health, whereas short rest periods are not associated with their mental health. This suggests that the strain of night work is a more important determinant of mental health for blue-collar workers. The differences in the relationship between work schedule characteristics and workers' mental health for white-collar and blue-collar workers can be explained in terms of different work styles, different expectations, and different degrees of selection. We conclude that working for long hours or irregular hours deteriorates the mental health of workers but its impact is likely to differ significantly across job types.

Using several kinds of micro data from household, employee, and retrospective surveys, this study examines the increase in the working hours of regular male employees in Japan during the serious recession of the early 2000s. The most important finding of this study is that working hours tended to be long among regular male employees in firms with major employee adjustments. The results suggest that the existence of abundant fixed duties necessary to maintain the internal organization of a firm primarily account for the increase in working hours of male employees during the recession. J. Japanese Int. Economies 36 (2015) 1-24. The University of Tokyo, Institute of Social Science, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; Waseda University, Faculty of Education and Integrated Arts and Sciences, 1-6-1 Nishiwaseda, Shinjuku-ku, Tokyo 169-8050, Japan; Keio University, Faculty of Economics, 2-15-45 Mita, Minato-ku, Tokyo 108-8345, Japan. (C) 2015 Elsevier Inc. All rights reserved.

By using both macro- and micro-level data, this paper investigates how wages and prices evolved during Japan's lost two decades. We find that downward nominal wage rigidity was present in Japan until the late 1990s, but disappeared after 1998 as annual wages became downwardly flexible. Moreover, nominal wage flexibility may have contributed to Japan's relatively low unemployment rates. Although macro-level movements in nominal wages and prices seemed to be synchronized, such synchronicity is not observed at the industry level. Therefore, wage deflation does not seem to be a primary factor of Japan's prolonged deflation.

By using a unique dataset on managerial-level employees who were transferred from Japan to European branches of the same global firms, we examine what would happen to work hours when a worker moves from a long-hour-working country to relatively shorter-hour countries. Even after controlling for business cycles, unobserved individual heterogeneity, job characteristics, and work hour regulations, we find a significant decline in Japanese work hours after their transfer to Europe, resulting from working-behavior influences of locally hired staff. We also find that the reduction in hours worked highly depends on the extent of the workers' interactions with local peers. © 2013 Springer Science+Business Media New York.

Using information on Japanese males' work hours and the matched firms' characteristics, this paper investigates whether the number of hours worked is determined by demand-side factors and tries to offer a possible explanation of why Japanese males tend to work longer on average, than their counterparts in other countries. Based on an empirical framework in which each firm sets a minimum boundary of work hours and where workers hired by the firm are required to put in at least the minimum hours, we found that the minimum requirement depends on each firm's fixed costs of labor. Specifically, firms that tend to hoard labor during recessions, presumably because of higher fixed costs, require incumbent workers to work longer hours during normal times. Since Japanese firms have long been considered as incurring high fixed costs to train workers, we interpret the long work hour requirement as a rational strategy for Japanese firms in protecting high-skill-accumulated workers from dismissal. In other words, the long work hours of Japanese males reflect firms' long-term employment practices, a typical feature of the Japanese labor market. J. Japanese Int. Economies 29 (2013) 57-73. Waseda University, Faculty of Education and Integrated Arts and Sciences, Japan; Keio University, Faculty of Business and Commerce, Japan. (C) 2013 Elsevier Inc. All rights reserved.

Kuroda, Sachiko, and Yamamoto, Isamu-Impact of overtime regulations on wages and work hours
Exploiting an ambiguity in the criteria regarding which employees are exempt from overtime regulations in Japan, this paper used the longitudinal data of Japanese employees to examine whether overtime regulations have an impact on hourly wages and hours worked. We found that although the differences between the hourly wages of the exempt and non-exempt employees were negligible, the hours worked by exempt employees were longer, especially for non-university graduates during the recessionary period. We interpreted that the fixed-wage model, rather than the fixed-job model, was prevalent during the recession period, especially for workers with low bargaining power. J. Japanese Int. Economies 26 (2) (2012) 249-262. Waseda University, Faculty of Education and Integrated Arts and Sciences, 1-6-1 Nishiwaseda Shinjukuku, Tokyo, japan; Keio University, Faculty of Business and Commerce, 2-15-45-502 Mita Minato-ku, Tokyo, Japan. (C) 2012 Elsevier Inc. All rights reserved.

Using data from a Japanese time use survey, we show a noteworthy increase in the share of employees working at unusual hours (late night and early morning) over a period of a decade since the mid-1990s. When controlling for changes in hours worked, however, we find that the notable increase in the fraction of people at work at unusual hours was for low-income nonregular employees (part-time, temporary and contract workers) while relatively higher income regular employees' work timing remains stable. These observations imply that there is a trend of diversification of work timing in Japan between regular and nonregular employees. A possible explanation is that the increase in the average hours worked per weekday by regular employees, possibly because of the spread of the 5-day workweek since the 1990s, increased services and goods demand at unusual hours as they returned home. An Oaxaca-Blinder type decomposition suggests that such an increase in the average hours worked by regular employees explains partially the rise in the employment rate of nonregular employees at unusual times.

Kuroda, Sachiko-Do Japanese Work Shorter Hours than before? Measuring trends in market work andleisure using 1976-2006 Japanese time-use survey
Using Japanese time-use data from the Survey on Time Use and Leisure Activities (STULA), this paper measures trends in average hours worked (market work) and leisure for Japanese over the past three decades. OECD reports at least a 15% decline in market work for Japan since the 1970s. However, holding demographic changes constant, we found that market work per week increased from the 1970s until mid-1980s, and has been relatively stable for the last two decades for both male and female full-time workers. Furthermore, although the market work per week remained relatively constant since the mid-1980s, we found a significant change in the allocation of time to market work within the week during the period. Specifically, when dividing samples into weekdays (Monday-Friday) and weekends (Saturday and Sunday), average hours spent for market work per weekday among full-time males increased by 0.4 h since the mid-1980s, whereas a significant decline in market work on Saturday was observed. This suggests that people shifted their work time from Saturday to weekdays in response to the reduced work week introduced by the amendment of the Labor Standards Act at the end of 1980s. In the meantime, commuting time and home production had decreased by 3 h since the mid-1980s for full-time female workers, indicating that the average hours of leisure had increased for females even though market work remained the same. Interestingly, however, hours for sleep declined consistently over the last three decades, resulting in a 3-4 h reduction per week for both male and female workers. Lastly, a comparison of Japanese and US time-use data suggests that Japanese work much longer than their American counterparts. On average, Japanese males work 10 h longer per week, and Japanese females 7 h longer, than Americans, even after adjusting for demographic differences between the countries. J. Japanese Int. Economies 24 (4) (2010) 481-502. The University of Tokyo. Japan. (C) 2010 Elsevier Inc. All rights reserved.

Using Japanese data from the 1990s aggregated by prefecture, age group, and sex, we estimate Frisch labor supply elasticity, which has been seldom estimated in Japan. The change in labor supply can be decomposed into two labor-supply behaviors: extensive margin, indicating workers' entry and exit from the labor market; and intensive margin, indicating changes in hours of work in response to a wage change. Our estimates of the Frisch elasticity on the extensive and intensive margins combined are in the range of 0.2 to 0.7 for males, 1.3 to 1.5 for females, and 0.7 to 1.0 for both sexes. Our estimates of the Frisch elasticity on only the intensive margin are in the range of 0.1 to 0.2 for all three categories. These results suggest that extensive margin explains the bulk of labor-supply changes in Japan. As for the changes in the estimates of the Frisch elasticity in Japan from the 1990s, it has been either unchanged or in a declining trend on the extensive and intensive margins combined, either unchanged or in a slight rising trend on only the intensive margin, and in a declining trend on only the extensive margin. J. Japanese Int. Economies 22 (4) (2008) 566-585. Hitotsubashi University, Japan; Keio University, Japan. (C) 2008 Elsevier Inc. All rights reserved.