2Yuengert A M.The Measurement of Efficiency in Life Insurance:Estimates of A Mixed Normal-gamma Error Model[J].Journal of Banking&Finance,1993,17(2):483-496.
3Cummins J D,Zi H.Comparison of Frontier Efficiency Methods:An Application to the US Life Insurance Industry[J].Journal of Productivity Analysis,1998,10(2):131-152.
4Jeng V,Lai G C,Mc Namara M J.Efficiency and Demutualization:Evidence from the US Life Insurance Industry in the 1980s and 1990s[J].Journal of Risk and Insurance,2007,74(3):683-711.