While some recent reports show guarded optimism for PR spending, Silicon Valley firms are still feeling the powerful crunch of a down economy and the high-tech implosion. A new study by McKie Headstrom PR shows PR spending in the Valley remains down and will continue to be down through 2003: McKie Headstrom surveyed PR execs at more than 600 private and public technology companies in the Silicon Valley area. More than half of respondents report they will not increase PR spending in 2003. The ray of hope: Of the third of respondents who said they increased spending in 2002, half will increase again in 2003.