Foreword to the special issue devoted to Professor Ivar Ekeland’s 70th birthday

[1] Brenier Y(1991)Polar factorization and monotone rearrangement of vector-valued functions Comm. Pure Appl. Math. 44 375-417

[2] Carlier G(2004)The structure of cities J. Glob. Optim. 4 371-376

[3] Ekeland I(1999)Aggregation and market demand: an exterior differential calculus viewpoint Econometrica 67 1435-1458

[4] Chiappori P-A(1974)On the variational principle J. Math. Anal. Appl. 47 324-353

[5] Ekeland I(2007)Optimal derivatives design for mean-variance agents under adverse selection Math. Financial Econ. 1 57-80

[6] Ekeland I(1996)The geometry of optimal transportation Acta Math. 177 113-161

[7] Ekeland I(2002)On the internal structure of cities Econometrica 70 1445-1476

[8] Carlier G(1998)Ironing, sweeping and multidimensional screening Econometrica 66 783-826

[9] Gangbo W(undefined)undefined undefined undefined undefined-undefined

[10] McCann RJ(undefined)undefined undefined undefined undefined-undefined

[1] Brenier Y(1991)Polar factorization and monotone rearrangement of vector-valued functions Comm. Pure Appl. Math. 44 375-417

[2] Carlier G(2004)The structure of cities J. Glob. Optim. 4 371-376

[3] Ekeland I(1999)Aggregation and market demand: an exterior differential calculus viewpoint Econometrica 67 1435-1458

[4] Chiappori P-A(1974)On the variational principle J. Math. Anal. Appl. 47 324-353

[5] Ekeland I(2007)Optimal derivatives design for mean-variance agents under adverse selection Math. Financial Econ. 1 57-80

[6] Ekeland I(1996)The geometry of optimal transportation Acta Math. 177 113-161

[7] Ekeland I(2002)On the internal structure of cities Econometrica 70 1445-1476

[8] Carlier G(1998)Ironing, sweeping and multidimensional screening Econometrica 66 783-826

[9] Gangbo W(undefined)undefined undefined undefined undefined-undefined

[10] McCann RJ(undefined)undefined undefined undefined undefined-undefined