Keywords: tax gap, tax evasion, personal income taxes, business taxes, microsimulation, input-output table.
The methods generally used to estimate the loss of revenue from tax evasion
can be divided into two types: the macroeconomic approach (or top-down) and the micro (or
bottom-up). The first is based on a comparison between fiscal data from Ministry of Finance
and aggregate data from national accounts; the second compares the income declared by the
taxpayer at a micro level with those obtained through sample surveys or those observed after
the auditing activity of the tax authorities.
This paper presents some preliminary results of the tax gap estimate in Tuscany for
three kinds of levies. As regards the personal income tax (IRPEF) we use a micro approach
by comparing the tax estimated in the survey on Income and Living Conditions (EU-SILC)
(where the gross income is bound to National Accounts) and fiscal data from Ministry of Finance.
In order to estimate the tax evasion on the regional tax on productive activities (IRAP)
we use a macro approach which compares the aggregate tax base from regional input-output
tables and the one from Ministry of Finance. Finally we propose an estimate of tax evasion
on the municipal property tax (ICI) by comparing the revenues estimated in the Italian land
register (Catasto) and those resulting from the municipalities' balances (Certificati Consuntivi