  Massive large-scale AGN outflows are an important element of galaxy
evolution, being a way through which the AGN can affect most of the host
galaxy. However, outflows evolve on timescales much longer than typical AGN
episode durations, therefore most AGN outflows are not observed simultaneously
with the AGN episode that inflated them. It is therefore remarkable that rather
tight correlations between outflow prop- erties and AGN luminosity exist. In
this paper, I show that such correlations can be preserved during the fading
phase of the AGN episode, provided that the AGN lumi- nosity evolves as a power
law with exponent $\alpha_{\rm d} \sim 1$ at late times. I also show that
subsequent AGN episodes that illuminate an ongoing outflow are unlikely to
produce outflow momentum or energy rates rising above the observed
correlations. However, there may be many difficult-to-detect outflows with
momentum and energy rates lower than expected from the current AGN luminosity.
Detailed observations of AGN out- flow properties might help constrain the
activity histories of typical and/or individual AGN.
