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 properties 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 luminosity evolves as a power law with exponent \alpha _ { 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 outflow properties might help constrain the activity histories of typical and/or individual AGN .