When should I automatically create an object even if `new` is forgotten?

Question

Let us say I have the following object constructor:

function Foo(bar) {
    this.bar = bar;
}

If I run the function in the global scope wit

Answer 1

While I don't have anything against that style, I would not personally use it just to be consistent. Sure, I can make all my constructors like this but it would seem like a lot more code to write.

If I'm worried about accidentally invoking a constructor without new, I would rather use JSHint to warn me about it. See http://www.jshint.com/docs/options/#newcap.