Tax avoidance schemes can be rendered ineffective through the use of a powerful tool known as the "business purpose" test. This test is used to identify artificial schemes that aim to avoid or minimize taxes. If a scheme does not have a legitimate business purpose, it can be disregarded and the taxpayer may still be subject to tax. In other words, the tax laws are designed to prevent individuals from exploiting loopholes for personal gain. So, it is important to understand the concept of "business purpose" in order to comply with tax regulations and avoid potential consequences.