Stella McKay, age 15, of Decatur,Ill., for her question:    

WHAT IS A CLOSED SHOP?

A closed shop is an industrial plant or workshop in which only members of a labor union may be hired.

It used to be that when some closed shops needed additional employees they were supplied only by the union's office. When employees had to be replaced or when new ones were needed, the employer had to go through union headquarters.

The closed shop was declared illegal by the Taft Hartley Act of 1947. However, the union shop is not illegal.

In a union shop, an employer may hire non union employees, but the new workers must join the union within a short period of time after they have been hired.