In this paper it is shown that in the design of a system of intergovernmental transfers based on fiscal capacities and fiscal needs it is important not to create perverse incentives for the sub-national governments. Several proposals for Argentina assume that the tax-rate elasticities of the tax bases are zero and, in this way, the sub-national governments cannot modify their standard fiscal capacity. In general terms, when these elasticities are different from zero, the jurisdictions will have incentives to manipulate tax rates to obtain higher transfers. They will also have incentives to hide tax bases. To avoid these manipulations fiscal capacities and fiscal needs must be estimated using exogenous data for these governments.