While many restaurants and restaurant chains are getting killed by the economic downturn, P.F. Chang's is up, up, up according to Slate's Dan Gross: "P.F. Chang's China Bistro, whose two restaurant chains--P.F. Chang's and Pei Wei Asian Diner--are staples of upscale malls and mixed-use developments, said that same-store sales fell a bit but profits produced at its 350 outlets rose 38 percent from the first quarter of 2008. Operating margins--the holy grail of any business--at P.F. Chang's 190 stores rose from 12.8 percent to 14 percent, largely because of 'incremental operational improvement opportunities.' The stock has doubled since November."