Indirect long-term effects are effects on the long-run future from interventions targeted at the short-term. Other terms that have been used for this concept or somewhat similar concepts include flow-through effects,^[1][2][3][4] ripple effects,^[5][6] knock-on effects^[7][8][9] and cascading effects.

When evaluating the outcome of an action, a distinction can be made between the action’s direct and indirect effects. Although the boundary between these two categories is often imprecise, direct effects are those effects that are relatively obvious and intended. Indirect effects, in turn, are effects that are either non-obvious (i.e., it is difficult to determine whether or to what extent they follow from the relevant actions), unintended, or both.

For instance, reduced malaria incidence is a relatively direct effect of bed-net distribution, whereas more indirect effects may include improved education and increased GDP growth (which in turn may have even further long-run effects).

Many kinds of indirect effects have received attention within the effective altruism community, including negative side-effects of disseminating true information, negative-side effects of rule-breaking, and replaceability effects.