The tag is fine to use without an href attribute. Contrary to many of the answers here, there are actually standard reasons for creating an anchor when there is no href. Semantically, "a" means an anchor or a link. If you use it for anything following that meaning, then you are fine.
One standard use of the a tag without an href is to create named links. This allows you to use an anchor with name=blah and later on you can create an anchor with href=#blah to link to the named section of the current page. However, this has been deprecated because you can also use IDs in the same manner. As an example, you could use a header tag with id=header and later you could have an anchor pointing to href=#header.
My point, however, is not to suggest using the name property. Only to provide one use case where you don't need an href, and therefore reasoning why it is not required.