Which effect does clause 18 of article i, section 8, which is known as the "elastic" or "necessary and proper" clause, have

Clause 18 of article I, section 8, which is known as the "elastic" or "necessary and proper" clause, have effect as it gives the government the powers to adapt to the modern needs and make laws in accordance with contemporary situations.

Explanation:

U.S. constitution has what is known as elastic or necessary clause enshrined under Article I, section 8 and clause 18. This empowers the government to make laws on the subject matter which is otherwise not expressly listed under Article I.

It is more like a residuary clause that can be expanded like elastic to cover and issue or matter which the country is facing and there is a requirement of any law or codification on such matter or issue. Hence, it helps the government to adapt to the modern needs of the time by still being governed by the more than 200 years old constitution.