Is it preferable to have # in a link's href attribute when I am implementing the click event via jQuery, or is it ok to leave href empty?

i.e.

<a id="myLink" href="#" />

vs

<a id="myLink" href="" />

When I'm doing

$("#myLink").on('click', function() {
   // do ajaxy stuff
});

Although I understand the click event could be on a span or other such element I'm interested in this case for particular best practices when using an a tag.