People have less expendable income, libations are usually the first to go. Starbucks and other coffee outlets had this problem a few years ago and they adjusted, offering more and making a less expensive option available. They managed to maintain their customer base and kept people walking in the doors.
Make a better product for less money, bottom line.
I don't believe that is true. Beer, especially, is relatively insulated from economic swings, and beer consumption may increase during recessions as consumers scale back their purchase of more expensive liquors.