- 著者
- IKEDA Shin S.
- 出版者
- GRIPS Policy Research Center
- 雑誌
- GRIPS Discussion Papers
- 巻号頁・発行日
- vol.16-03, 2016-06
I construct data on the numbers of workers and suicide victims in their working ages in Japan from 1980 to 2010 for each of 10 occupation classes and for males and females separately. I document a complex transition of the job profiles of occupation classes, and establish a correspondence between Japanese and international job classifications. Four general characteristics of occupation-wise suicide risk in Japan emerge from graphical analyses of constructed data. First, heterogeneous aging patterns of suicide deaths and numbers of workers create complex aging patterns of suicide rates. Second, the age-adjustment and stabilizations of suicide rates are crucial for an accurate measurement and a fair comparison of suicide risk for workers in each occupation or over the entire economy. Third, the surge of overall suicide risk in Japan since 1998 might be driven by that in few occupations for each gender. Particularly, (a) a high suicide-risk profiles for male workers in agricultural, forestry and fishery and jobless categories has been stable over time, hence not a main culprit of such surge, and (b) less informative patterns of female suicide rates may be a consequence of the cancellations of higher suicide risk in some occupations and lower suicide risk in any other occupations during such surge. Fourth, gender- and occupation-wise pattern of suicide risk is further confounded with heterogeneity across regions.
- 著者
- IKEDA Shin S.
- 出版者
- GRIPS Policy Research Center
- 雑誌
- GRIPS Discussion Papers
- 巻号頁・発行日
- vol.15-04, 2015-05
Historical data of system prices and traded quantities of electricity over the 48 half-hour intra-daily intervals in the Japan Electric Power Exchange are analyzed. Viewed as a panel dataset of the 48 different commodities in 7 different markets (days of a week) or 336 different contracts over 288 weeks, the data allow me to compute two representative measures of illiquidity, namely, Amihud's price-impact measure and Roll's implied spread cost measure from November 2006 to April 2012. These measures are based on the absolute weekly returns of each of 336 contracts divided by the corresponding volume of traded electricity, and on the first-order serial covariance of weekly returns, respectively. Two measures closely comove but they contribute to the returns in different magnitudes, suggesting that each of them captures both common and distinctive aspects of illiquidity in the JEPX market. Once the lagged returns are controlled for in a dynamic panel framework, the influence of price-impact measures on returns dominate that of spread measures. The price-impact measure and traded volume contribute the return variations in opposite signs, i.e., positively and negatively. It suggests that the assessment of illiquidity requires a careful treatment of these confounding factors.