Preferred citation style

摘要: Preferred citation style Page 1 Preferred citation style Hess, S. and KW Axhausen (2005) Distributional assumptions in the representation of random taste heterogeneity, 5th STRC, Ascona, March 2005. Page 2 Distributional assumptions in the representation of random taste heterogeneity Stephane Hess Imperial College London & RAND Europe Kay Axhausen ETH Zurich Page 3 Mixed Logit • No a priori constraints on choice of f(β|Ω) • No closed- form solution for choice- probabilities → Need simulation in estimation and application ( ) ( ) ( ) β β β β β d f e e P I j X f X f ni nj ni ∫ ∑             Ω = =1 , , Page 4 Issues for the a-priori distribution • Generally no a priori knowledge about true distribution • Limited set of distributions available in standard estimation packages • Most researchers/practitioners use Normal • Limited success with using alternative distributions Page 5 Current choices • Normal • …