Clark argues that Ballard's subjects made the patternofblocks part oftheirextended mind. Itbecame a store ofknowledge they could dip into, an externalrepositoryofinformation.
They note that the patchy growth often seen in the early quarters of an economic expansion for instance, the jobless recovery of the early 90s or the double-dip in 2002 is not usually reflected in the pattern of earnings recovery.