This is the passing of an era. Bill was a truly remarkable person. His intellect and his energy are rarely surpassed. His ability to embrace all was exemplary. We are the poorer for his passing.
Bill stands as a giant among us, distinguished for his intellect, his energy and his humanity. Most of us have come to know him from his seminal Work in Data Envelopment Analysis (DEA). However, Bill had a long and illustrious academic career well before he turned his hand to DEA. Indeed, he would have been well into his 60s before the seminal paper on DEA in the European Journal of Operational Research in 1978. Many academics at that age are looking into retirement, but that could not have been further from Bill’s mind at that time. As recently as 2008 when I was still one of the Editors of the Journal of Productivity Analysis he was urging me to get his paper reviewed and a decision made quickly because as he put it ‘I am into my 90s and I do not have long to go’! One can scarcely take in the magnitude of the revolution Bill and his co-authors (Charnes and Rhodes) unleashed with their seminal paper on DEA. The Scopus database reveals that their 1978 paper on DEA has till now (2012) close on 5000 citations. This is 5 times more than the next most cited paper (Saaty’s AHP). There are over 5000 publications in DEA covering theory and applications in areas spanning the entire alphabet from Agriculture to Zones of gas distribution. Bill stood in the 40 years since the seminal paper on DEA as the longest serving father of DEA with a steady stream of contributions throughout that period. Bill was a passionate proponent of the virtuous circle of practice-relevant research where applications benefit from research findings while at the same time they point to new research avenues to be explored. DEA lends itself particularly well to this type of research. I first met Bill at a conference on DEA in 1989 in Austin Texas. We continued to keep in touch since that time. I have benefited tremendously from his research. He often sent me his papers which might have just appeared or were even at a working paper stage. Away from his research Bill was an extremely friendly person. He always had time for people despite being extremely busy. He was supportive of researchers, co-authoring papers with those taking their first steps in DEA and offering friendly advice whenever asked. He was a remarkably kind and considerate person. We are lucky to have known Bill. The DEA community will undoubtedly be the poorer for his passing. However, we can be grateful that he enjoyed a very long and creative life. In my memory at least he will live as long as I live.RIP Bill. Emmanuel Thanassoulis, UK August 2012