The economic rates of return for utility privatization projects in Argentina are very high, whether or not distributional weights are considered. But there is a very high shadow price for regulatory activity, which tends to be ignored in most privatization exercises. And how serious a government is about the fair distribution of gains from reform is reflected in how serious it is about regulation. Chisari, Estache, and Romero assess the macroeconomic and distributional effects of the privatization that Argentina began in 1989 in gas, electricity, telecommunications, and water and sanitation. Using a computable general equilibrium model, they track the effects of the changes observed between 1993, the first year by which all the major privatizations had taken place, and 1995, the most recent year for which data are available. In an innovative use of the model, they also assess the importance of the regulator in determining the distribution of gains and losses from utility privatization among sectors and income groups. They conclude that when regulators are effective, the annual gains from the private operation of utilities are about $3.3 billion, or 1.25 percent of GDP, and that all income classes benefit. Ineffective regulation cuts the gains from the reform by $1 billion or 0.35 percent of GDP. This cut in gains represents an implicit tax of 16 percent on the average consumer, paid directly to the owner of the utility rather than to the government. For the poorest income classes, this implicit tax is about 20 percent, meaning that good regulation is in the interest of the poor. The authors also show that the privatization of utilities cannot be blamed for the significant increase in unemployment observed in Argentina since 1993. Effective regulation can lead to a decline in unemployment, and ineffective regulation leads to only a small increase in unemployment. But the gains from utility privatization were not sufficient to offset the negative efficiency and distributional impact on the economy of the Tequila effect, which increased unemployment dramatically by limiting access to credit for users and producers alike. This paper-a product of the Regulatory Reform and Private Enterprise Division, Economic Development Institute-is part of a larger effort in the institute to understand the importance of effective infrastructure regulation. The study was funded by the Bank's Research Support Budget under the research project "Efficiency and Equity Implications of Argentina's Privatization of Infrastructure Services" (RPO 680-85).