Yacov Tsur Professor U of Minnesota   Dep. of Agric Econ & Mngment Hebrew University of Jerusalem POB 12 Rehovot, 76100 Israel   tsur@agri.huji.ac.il   http://www.agri.huji.ac.il/~tsury/           JEL Areas: Q5 : Environmental Economics: General E6 : Macroeconomic Policy, Macroeconomic Aspects of Public Finance, and General