Have you spoken to him about it?
I would be asking why he feels the need to drink on his own and during the day, it could be the beginning of a depressive downward spiral with being out of work, less money and more time on his hands, add alcohol into the equation and it could get nasty in time.
Ray
Hard to say. Alcoholism is not about how much you drink or how often you drink but when you conitnue to drink despite the negative impact drinking is having on your life.
Is he drinking when he should be looking for a job or going on interviews?
It's a tough call as to wether he's an alcoholic or not. He's clearly being unhealthy if he's drinking as much as it seems but it might be his way of coping with his unfortunate and frustrating situation. Not that that's a healthy way to do it or a good idea by any means but some people will lose a job, break up with their bf/gf, lose a loved one, etc... and go on a bender for a week or two... the alcoholic continues drinking after that. The non-alcoholic blows off their steam and then snaps out of it and goes back to work.
Either way he's clearly stuck in a rut, he's pobably down on himself, frustrated, and depressed. See if you can't take him out (not drinking), cheer him up a bit. Encourage him to keep looking for work, maybe take what he can get for now, etc.. just get back in the workforce and not home on the couch drinking. If he makes all sorts of excuses as to why he can't/shouldn't then he may be developing an unhealthy attachment to the booze. Of course you may need to convince him but if he's thinking logically he'll see that you're right.
This is a tough and trying time for a lot of people. I'm certainly not going to begrudge the guy a few weeks of being mopey or angy, blowin' off some steam... but sooner rather than later he has to at least make the effort to get back on his feet and go to work.