数据:所有A股上市企业
变量:股票代码,年份,HHI(赫芬达尔-赫希曼指数),CR4(4个最大企业的市场份额率),CR10(10个最大企业的市场份额率)
样例如下:
stkcd | year | hhi | cr4 | cr10 |
2 | 2000 | 0.051645 | 0.373856 | 0.568852 |
2 | 2001 | 0.048963 | 0.359638 | 0.555583 |
2 | 2002 | 0.044121 | 0.320246 | 0.549767 |
2 | 2003 | 0.051037 | 0.353674 | 0.573319 |
2 | 2004 | 0.044628 | 0.319051 | 0.544449 |
2 | 2005 | 0.058817 | 0.338826 | 0.54012 |
2 | 2006 | 0.072383 | 0.373813 | 0.569376 |
2 | 2007 | 0.083734 | 0.420661 | 0.586644 |
2 | 2008 | 0.081036 | 0.440321 | 0.602983 |
2 | 2009 | 0.066488 | 0.402196 | 0.561413 |
2 | 2010 | 0.044344 | 0.344546 | 0.484113 |
2 | 2011 | 0.052829 | 0.374978 | 0.504246 |
2 | 2012 | 0.062114 | 0.416263 | 0.553085 |
2 | 2013 | 0.067034 | 0.424637 | 0.569836 |
2 | 2014 | 0.065838 | 0.432142 | 0.587839 |
2 | 2015 | 0.075529 | 0.482124 | 0.619542 |
2 | 2016 | 0.067921 | 0.454775 | 0.602912 |
2 | 2017 | 0.068447 | 0.453342 | 0.602212 |
2 | 2018 | 0.067423 | 0.44683 | 0.614944 |
2 | 2019 | 0.071762 | 0.458079 | 0.642354 |