摘要：Revenue mobilization is an important goal of tax reform. Thus, tax buoyancy constitutes an essential ingredient for tax policy formulation. This paper utilized a time series approach to estimate tax buoyancy for Kenya for the period 1999/2000 to 2010/2011. Tax buoyancies were computed for income, import, excise, Value Added Tax (VAT) and total taxes. Specifically, the paper examined the buoyancies of tax revenues to changes in economic growth (GDP) and proxy bases using quarterly data instead of annual data of GDP and tax revenues and their bases. This was because tax revenue data are collected and reported as per fiscal year, which starts on 1st July each calendar year and ends on 30th June the following year. We also analyzed the tax buoyancy of Pay as You Earn (PAYE), other income tax, as components of income tax and local and import VAT as components of total VAT. This was done to ascertain the response of these specific taxes to their bases. Empirical evidence showed that the total tax was buoyant with a buoyancy value of 2.58 while the individual taxes were not buoyant except the excise duty which was buoyant with respect to the base. Tax bases were found to respond well to economic changes with buoyancy values greater than unity, with an exception of excise duty base to income buoyancy coefficient being less than unity. Based on these findings, we recommend constant review of the tax system as the economic structure changes. Reasons for tax evasion should also be analyzed to help minimize noncompliance.
