® The Erlang Prize is presented by the Applied Probability Section of the Institute of Operations Research and Management Sciences, to the outstanding young applied probabilist Xiui Chao The 1998 Erlang prize is awarded to Xiuli Chao for his wide range of contributions to Applied Probability. Most significant is an extensive study by Chao and his collaborators of the class of Markovian networks which exhibit product-form stationary distributions. This class of networks encompasses Jackson and Kelly networks, networks with negative customers, and signaling networks. In other investigations, Chao used stochastic convexity to establish an important monotonicity property for doubly stochastic Poisson processes and has studied interchangeability and reversibility properties of tandem queues with finite buffers and blocking. Chao has also made contributions to stochastic scheduling and mathematical finance. In addition to an outstanding record of research and publications, Chao has served on the editorial boards of many leading journals and it a co-author of books and queueing networks and operations scheduling which soon will appear. The breadth of his contributions merit the highest level of recognition by the Applied Probability community. Lawrence Wein, Applied Probability Chair Peter W. Glynn, AP Prize Committee Chair Martin L. Puterman J. George Shanthikumar April 27, 1998