42 | II Série C - Número: 023 | 9 de Fevereiro de 2008

concorrência fiscal em particular dos seus benefícios ou malefícios. A Caixa 2 apresenta uma síntese dos argumentos contra e a favor. Um outro aspecto que contribui para a falta de consenso consiste nas diferenças estruturais de natureza técnica entre os sistemas fiscais, em especial no tocante ao nível, estrutura, incidência e taxas.

Caixa 2 — Concorrência fiscal: argumentos contra e a favor

“A question that is often raised is whether tax competition is a positive phenomenon. Should countries welcome it or not? On this question views diverge. Some and especially theoretical economists and those with public choice bent tend to see it as a beneficial phenomenon. On the other hand, many ministers of finance, directors of taxation and policy-oriented economists tend to see it as a negative, and possible a significant problem

Arguments in Favour of Tax Competition (a) It forces countries to lower tax rates especially on mobile tax bases such as financial capital, highly skilled workers, and so on. Lower tax rates imply lower welfare costs.
(b) By reducing tax revenue, it forces governments to reduce inneficient public spending. This is the “starve the beast” theory that was favoured by the Reagan Administration.
(c) It may allocate world savings toward areas were, it is claimed, the savings are used more productively.
This was a common claim made by the representatives of the US Government in the first half of the 1980s.
(d) Because of lower tax revenue, it may force policymakers to re-think the role of the state.
(e) It may lead to a tax structure more dependent on immobile tax bases. Economists would consider these bases less distortional for the economy.

Arguments in Against of Tax Competition (a) Because public spending may be politically or legally inflexible downward, at least in the short and medium run, the consequence of tax competition could be, for some countries, increased fiscal deficits and public debts.
(b) When public spending is cut, there is no assurance that what will be cut will be the inefficient part of the public spending. Inefficient spending may have stronger constituencies to defend it. For example, experience shows that capital spending tends to be reduced more than current spending.
(c) Tax competition may lead to “tax degradation” because governments may try to mantain public revenue by introducing bad taxes to replace lost revenues. An example of this is a tax on financial transactions introduced in recent years by several countries, especially in Latin America.
(d) Governments may replace public spending with inefficient public regulations. This has happened in various countries in the past.
(e) The shit of the tax burden from mobile factors (such as financial assets and highly skilled individuals) to immobile factors (largely labour income) will tend to make the tax system less fair and may increase pressures for redistributive public spending.
(f) The increased taxes on labour income are likely to stimulate growth of the underground economy and, as a consequence, the growth of tax evasion.” Fonte: Vito Tanzi, Globalization and tax systems, 15 Anos da Reforma Fiscal Jornadas de Homenagem ao Professor Pitta e Cunha, Almedina, 2005, pp. 699-700.

7 Como realça a definição de concorrência fiscal apresentada na Caixa 1, nas políticas fiscais de base, os Estados podem abrir excepções, derrogações, etc., com base no intuito específico de atrair e reter a presença de empresas no país. Isto pode ser, de acordo com essa definição, considerado concorrência prejudicial.
Estes incentivos podem também, segundo a mesma definição, revestir a forma de auxílios estatais.