Question

externalities are effects. intended spillover always negative

Explanation:

Externalities refer to the spillover effects of economic activities on third - parties. They are not the intended effects of the economic transaction (so not "intended"). Also, externalities can be positive (e.g., a beekeeper's bees pollinating a neighbor's flowers) or negative (e.g., pollution from a factory), so they are not "always negative". The term "spillover" accurately describes externalities as they are the side - effects of economic actions on others.

Answer:

spillover