本文基于公司所得税竞争可能会造成税基被不断侵蚀这一担心,通过计算有效平均税率来测量公司所得税竞争(包括普遍使用的免税期)对加勒比海地区15个国家的税基所产生的影响。研究结果证实:税基确实受到了侵蚀,同时还表明,要使得最近的税收政策(如加速折旧、损失后转及税收协调政策)有效实施,必须取消公司所得税免税期。研究结论表明,各国政府要拓宽税基,就必须取消公司所得税免税期,或者更多地依赖其他税种(包括消费税各税种如增值税等)。 This article is based on the concern that corporate income tax competition may lead to a continuous erosion of the tax base by measuring the effect of corporate income tax competition, including the commonly used tax holidays, on the tax base of 15 countries in the Caribbean. The results of the study confirm that the tax base has indeed eroded and at the same time shows that tax exemption periods for corporate income tax must be abolished in order to effectively implement recent tax policies (such as accelerated depreciation, loss recovery and tax coordination policies). The conclusion of the study shows that if governments want to broaden their tax base, they will have to cancel the corporate tax holiday or rely more on other taxes (including excise taxes, such as VAT).