Takayoshi Kusago Kansai University, Osaka, Japan   3-3-35, Yamate-cho 3-3-35, Yamate-cho Suita-shi Osaka, Osaka 564-8680 Japan   tkusago@kansai-u.ac.jp             JEL Areas: C8 : Data Collection and Data Estimation Methodology; Computer Programs: General D3 : Distribution: General