The October 2004 issue of this journal was a part-special issue comprising eight papers on Data Envelopment Analysis edited by A Emrouznejad, RH Green and VE Krizvonozhko. The papers had been presented at a Symposium in 2002. In this issue; we include three further papers from the same Symposium. The papers are:

FJ Arcelus and P Arocena, ‘Productivity differences across OECD countries in the presence of environmental constraints’.

B Casu, D Shaw and E Thanassoulis, ‘Using a group support system to aid input–output identification in DEA’.

VE Krivonozhko, OB Utkin, AV Volodin and IA Sablin, ‘About the structure of boundary points in DEA’.

These papers make further contributions to the state of knowledge of Data Envelopment Analysis.