jQuery given input ID, get label text

In my HTML forms (as in most HTML forms), the labels share the same IDs as the fields. I'm trying to return to HTML of the label tag once the checkbox with a matching ID is clicked.

<input id="yes1" type="checkbox">
<label for="yes1">This is the text it should return.</label>

And my jQuery:

$('input').change(function() {
    if (this.checked) {
        var response = $('label#' + $(this).attr('id')).html();
    }
}

But alas, response comes out as NULL.