The economy is still growing, but just barely. The latest wave of downbeat economic data, including Friday’s report on gross domestic product, have renewed fears that we could be headed for the second half of a “double dip” recession. It is even possible that the apparent economic recovery is a mirage, and that the recession that began in December 2007 never really ended. Increasingly it seems that the unprecedented measures taken in 2008 and 2009 to revive the economy are not working because the recession is unlike any this country has seen in the past 60 years.