Shanthikumar, J. George; Yao, David D. - In: Stochastic Processes and their Applications 23 (1986) 2, pp. 259-267
Unlike stochastic ordering ([greater-or-equal, slanted]st), which is preserved under convolution (i.e., summation of independent random variables), so far it is only known that likelihood ratio ordering ([greater-or-equal, slanted]lr) is preserved under convolution of log-concave (PF2) random...
