In the article the author focuses his attention on the problem of interaction through the tax system on economic activity. The main issue is raised here the problem of rational use of fiscal instruments to stimulate the behavior of taxpayers, that are beneficial from the standpoint of fiscal policy objectives. In this context, author discusses the problem of the relationship between the level of tax burden and the size of the shadow economy and the issue of relocation. The conclusion is that excessive tax burdens have a negative impact on activity by registered enterprises, may decrease the competitiveness of the economy and stimulate harmful activities from a social and economic point of view. In contrast, the experience of many OECD countries shows that it is worthwhile to reduce the fiscal burden.