The
cost or benefits of a
transaction to parties who do not directly participate in it. Externality can be either positive or negative. For example, a
merger can lead to higher share prices and
bonuses for employees, benefiting
shareholders and
employees at the two companies merging, This can create
wealth and positively impact a community. On the other hand, the merger can drive a competitor out of business, which results in
layoffs and reduced wealth, which can hurt a community. Externality is also called spillover or the neighborhood effect. See also:
External benefit,
External cost.