This paper develops a simple framework for investigating the variation
in firms' investment behavior across industrial sectors and over time
. We divide the economy into three tiers: major industrial sectors, bu
sinesses, and firms, and focus on the impact of business-level interac
tion on firms investment behavior. After controlling for unobservable
firm-specific effects, business-specific effects, and a changing econo
mic environment, we find that the investment and profitability of comp
etitors help explain variations in investment across firms in major Ja
panese industrial sectors. (C) 1998 Elsevier Science B.V.