This award provides funds to upgrade and expand both the servers and computer workstations used in the Pittsburgh Experimental Economics Laboratory (PEEL) which is housed on the University of Pittsburgh main campus and administered by the Department of Economics. PEEL's existing equipment was purchased with funds provided by a prior NSF grant Major Resource Instrumentation Grant awarded in 1997, NSF no. 9724620. Since that time, no major upgrades have occurred; the laboratory is in need of new equipment to replace the slow or inoperable computers and servers that are well beyond their expected lifetimes. PEEL has recently been used for experimental economics research by 21 faculty, 5 graduate students and 2 post-docs from 13 different universities. Much of this research is supported by NSF and other external grants that provide funds for subject payments, but not for hardware. Thus, the awards from this grant will complement a number of other NSF funded projects. Some of the research topics that have been or will be explored in the laboratory include experimental analyses of cooperation in repeated games, trust and reciprocity, status and relative concerns, learning, auctions, bargaining, equilibrium selection in coordination problems, the role of gender in competition, the emergence of money as a medium of exchange and asset pricing. Experimental methods often provide the only means of collecting data to test economic theories or to explore promising new hypotheses. The funds from this award will increase the number of PEEL's PC workstations from 30 to 40 and provide for faster servers. These improvements will enlarge the set of experimental environments that can be explored by PEEL researchers, as larger subject populations will be permitted and the increase in real-time processing will facilitate certain experiments such as those involving asset pricing. The upgrade will also have an educational benefit as it will ease enrollment caps on courses taught in PEEL. In addition to research and course use, the laboratory is an important training ground for graduate students. The University of Pittsburgh has provided a commitment of laboratory space and an annual operating budget that covers the salary of a laboratory administrator and graduate student research assistant. In addition, the University of Pittsburgh has invested heavily in faculty with research interests in experimental economics. In combination with the strong behavioral/experimental faculty at neighboring Carnegie Mellon University, the Pittsburgh experimental laboratory is one of the busiest laboratories devoted to experimental research in the world today. The much-needed upgrade of PEEL's computers and servers will ensure that PEEL remains a state-of-the-art computer laboratory for conducting experimental economics research for many years to come.