The eight case-study countries in this report--Bolivia, Colombia, Indonesia, Jamaica, Korea, Mexico, Morocco, Turkey--provide a laboratory for studying tax reform in practice. The countries vary not only in per capita income but also in the context within which tax reform takes place. They undertook different types of reform and the outcome differed. Several lessons emerge: 1) Although all countries are often forced to sacrifice the optimal tax structure in favor of a simpler, more uniform system, to conform to the administrative capacity of the country, the sacrifices can be especially large in developing countries. 2) Developing country tax systems need not be overly concerned with equity, since redistribution in these countries is best carried out by public expenditures. 3) Instances where obviously welfare-improving, even Pareto-improving, tax reforms are not undertaken illustrate the point that even reforms benefiting everyone may be opposed by the affected parties who perceive their bargaining power altered (and possibly reduced) in the longer run.