"To lag the effects" means that there is a delay between an action or event and its consequences or impact. It implies that the effects of something do not happen immediately, but instead take some time to manifest or be felt. Full definition
The fact that the southern oceans are absorbing heat may set up another interesting lag effect. (realclimate.org)
For a period after that, in the second half of 2001, the annual figure may then be held down by lagged effects of some indirect tax reductions. (rba.gov.au)
Lowered positive affect had the opposite lagged effect for people high in trait spirituality, who experienced small increases in spirituality, than for those low in trait spirituality, who experienced small decreases in spirituality. (positivepsychologynews.com)