关键词: 国际税法, 资本弱化, 公司股权津贴(ACE), 综合经营所得税(CBIT)

Abstract: The different tax treatments of debt and equity make thin capitalization more salient and should be brought under control. As two measures of solving these problems， allowance for company equity (ACE) and comprehensive business income tax (CBIT) have been carried out in some countries. ACE treats equity the same as debt， so interest can be deduced before levying tax， while under CBIT， interest can not be deduced before calculating the business income tax. Both of them are for keeping tax neutrality in investment. In terms of their economic impact， ACE leads to narrower tax base， higher tax rate and lower capital cost， while CBIT results in broader tax base， lower tax rate and higher capital cost. As to their impact upon investment， under ACE， the higher tax rate may decrease investors capital return and push multi-national companies to invest in lower tax rate countries. However， with capital cost decreasing， the return for investment will rise， which may attract more investment. Under CBIT， the increase of capital cost may cause investment to fall.

Key words: international taxation, thin capitalization, allowance on corporation equity(ACE), comprehensive business income tax(CBIT)