no if trend is defined as change from date to date
in potential max output
so how are actual used trend lines constructed ??
by a fleet of assumptions
like NAIRU barriers asnd minimum slack capacity
its voodoo nomics
at any rate
my point
a prog view would go like this
if output pierces the trend line then lost output is understated in all periods subject to that trend line
a new higher trend line needs to be constructed
why ? because real output can never exceed potential output
