The sky, apparently, is no longer falling: Just as many homebuyers began to believe that mortgage interest rates would never again increase, the average 30-year fixed rate ticked up to 4.35 percent this week, according to Freddie Mac, only the second time it has done so in the last 12 weeks. The average rate last week was 4.32 percent, a historical low since Freddie began recording rates in 1971. Though rates have been dropping since early 2010, home sales have not dramatically increased. Some commentators have suggested that rising rates might nudge some reticent homebuyers off the sidelines. Combine that fantasy with a significant and immediate improvement in the job market and we might have something we could call a recovery.