中文版：

为什么要加进口增值税

进口增值税，作为国际贸易中的一项重要税收，其存在和实施具有多方面的原因和必要性。

首先，进口增值税的征收有助于调节国内市场的供需平衡。对于某些国内生产不足的商品，适度降低进口增值税可以吸引更多的进口，从而满足国内市场的需求。而对于国内产能过剩的商品，适度提高进口增值税则可以有效抑制过度进口，保护国内产业的发展。

其次，进口增值税的征收是国家财政收入的重要来源之一。随着国际贸易的不断发展，进口商品的数量和金额逐年增长，征收进口增值税可以为政府提供稳定的财政收入，用于支持国家的经济发展和社会建设。

此外，进口增值税的征收还可以促进国际贸易的公平竞争。通过对进口商品征收增值税，可以平衡国内外商品的税收负担，防止国外商品以低价倾销的方式冲击国内市场，保护国内产业的健康发展。

综上所述，加进口增值税是出于调节市场供需、增加财政收入以及促进国际贸易公平竞争等多方面的考虑。然而，在征收进口增值税的过程中，也需要注意合理确定税率，避免对进口商品和国内产业造成过大的影响。

英文版：

Why Is Import Value-Added Tax Necessary?

Import value-added tax, as an essential tax in international trade, serves multiple purposes and holds significant necessity in its existence and implementation.

Firstly, levying import value-added tax helps regulate the balance of supply and demand in the domestic market. For goods that are insufficiently produced domestically, appropriately reducing import value-added tax can attract more imports, thus meeting domestic market demands. Conversely, for goods with excess domestic production capacity, moderately increasing import value-added tax can effectively restrain excessive imports and protect the development of domestic industries.

Secondly, the imposition of import value-added tax is a significant source of national revenue. With the continuous development of international trade, the quantity and value of imported goods have been increasing year by year. Collecting import value-added tax can provide stable fiscal income for the government to support national economic development and social construction.

Furthermore, levying import value-added tax can promote fair competition in international trade. By imposing value-added tax on imported goods, it can balance the tax burden between domestic and foreign goods, prevent foreign goods from flooding the domestic market through low-price dumping, and safeguard the healthy development of domestic industries.

In summary, imposing import value-added tax is motivated by various considerations, including regulating market supply and demand, increasing fiscal revenue, and promoting fair competition in international trade. However, it is also necessary to reasonably determine the tax rate during the imposition process to avoid excessive impacts on imported goods and domestic industries.