“…The first-difference estimator provides the better treatment for the endogenity problem, which is common to the firm-level data, as compared to the withintransformation estimator (Westbrook and Tybout 1993). However, the first-difference 15 7 Complied from the online database at http://www.boj.or.jp/type/stat/dlong/price/cgpi/index.htm 8 They are available for the following industries, textile products, iron and steel, non-ferrous metals, metal products, general machinery, electrical machinery, transport equipment, precision instruments, and other manufacturing industry products.…”