Before revision:  Using a unique data set covering 10 years of interfirm buyer--seller networks and structural equation modeling, we show that the evolution of the interfirm buyer--seller network is a result of a firm's myopic decisions to avoid other firms ' negative shocks and share their positive shocks.
After revision:  Using a unique data set covering 10 years of interfirm buyer--seller networks and structural equation modeling, we find some evidence that interfirm networks evolve reflecting a firm's myopic decisions to avoid other firms ' negative shocks and share their positive shocks.