332 A SHORT ANALYSIS ON THE SENSITIVITY OF TAX REVENUES IN ROMANIA DURING 2000 - 2009 Bunescu Liliana Lucian Blaga University of Sibiu Faculty of Economics Mihaiu Diana Marieta Lucian Blaga University of Sibiu Faculty of Economics From a temporal perspective, the collected tax revenues for the public budget know a number of changes in terms of flow and collection rates due to changes in factors of influence. The most used method to measure the response, the sensitivity of tax revenue to any changes of a variable is elasticity. This paper seeks to briefly examine the sensitivity of tax revenues to changes occurring in terms of gross domestic product and tax burden in Romania during 2000 to 2009. After analysis, we believe that a pattern regarding the sensitivity of tax revenues to the modification of a factor can not be created, tax elasticity developments and alternations of elasticity / inelasticity are not based on a uniform rule, they differ from country to country, and even in the same country from one period to another. Keywords: tax elasticity, tax burden, tax revenues JEL Classification: H 23, H 30 1. Introduction Taxes generate the biggest part of public resources and that is not a novelty. Currently, both theorists and practitioners` concerns are increasingly focusing on the question of the relative sizing of tax compared to its base of calculation and also compared to the source of taxes, source which is ultimately reduced and expressed in the purchasing power of taxpayers. Taxpayers are more interested in the net incomes and the extent to which these are affected by taxes. Tax burden indicates the degree of taxation, meaning the extent to which taxpayers as a whole, society, economy supports a range of taxes, such as compulsory levies, imposed and charged by the state through legal compulsion. Tax burden and the degree of taxation is a way of sizing the tax incidence. 2. Sensitivity of tax revenues based on GDP From a time perspective (short or long), tax revenues collected by the national public budget know a number of changes in terms of flow and collection rates due to changes of factors of influence. The analysis of the impact of changes in the factors of influence can be made by studying their magnitude. The most frequently used method of measuring the response, the sensitivity of tax revenue to the change of a variable, is elasticity. It can be measured by a coefficient of elasticity of tax revenues based on GDP and the tax rate, considering other factors unchanged (caeteris paribus). The elasticity of tax revenues based on GDP is the response or reaction of tax revenues to the movement or fluctuation in GDP. A null value of tax elasticity indicates that a variation towards infinity of GDP will determine an incomplete collecting of tax revenues as a result of the self- defense reaction of the taxpayer in front of taxes. Tax elasticity indicates the ratio of relative change in tax revenue and relative change in GDP for a particular country. It expresses the sensitivity of direct and indirect tax levies to changes of GDP or other conditions of public revenues (tax rate). The issue of quantify the degree of tax elasticity was questioned by other