如何用stata计算赫芬达尔指数

如何用stata计算赫芬达尔指数

赫芬达尔——赫希曼指数是用某特定市场上所有企业的 市场份额 的平 方和来表示，其公式为： 式中： X——市场的总规模 Xi——i企业的规模 Si＝Xi／X——第i个企业的市场占有率 n——该产业内的企业数

*version august 2012 -------------------- basic syntax: hhi var, by(varlist) [if exp] [in range] [outfile, replace] description: hhi generates herfindahl-hirschman index variables also commonly known as concentration index in econom > ics and finance. the module supports multiple variables and group ids and allows user to export outpu > t in table format (csv comma delimited). options ------- by(varlist): allows multiple groups defined by `varlist' e.g. (year, country, region) outfile: export data in table format (.csv comma delimited) examples: ---------- hhi x1 x2 hhi x1, by (year country region) hhi x1, by (year country region) outfile hhi x1 x2 x3, by(year country region) hhi x1 x2 x3, by(year country region) outfile replace author muhammad rashid ansari insead business school 1 ayer rajah avenue, singapore 138676 rashid.ansari@insead.edu (remote file ends)