Inferior goods are those good for which demand rises when incomes fall. It looks like McDonald's is lovin' the economic crash. Evidence that McDonald's meals are inferior goods.
Full service restaurant meals, on the other hand, are normal goods (and sometimes luxury - those whose demand rises faster than rises in income).
Makes me start to worry about what is going to happen to Portland's thriving restaurant scene...
By the way, a person in the business suggested to me that in an economic downturn bottled beer sales may go up while pints of beer served in pubs and brewpubs might see a significant decrease in sales. It will be interesting to see if bottled beers are inferior and fresh pub-served pints normal.