Price-setting behaviour, competition, and mark-up shocks in the New Keynesian model

Recent research and policy discussions have noted that the potentially increased competition among firms since the 1990s may affect inflation and economic activity. This paper considers the implications of this structural change on short-run inflation dynamics, and for assessing shocks to inflation and output. The importance of firms' price-setting behaviour is highlighted in this context using a standard New Keynesian model with microfoundations. It is well known that both Rotemberg and Calvo price-setting assumptions imply the same reduced-form New Keynesian Phillips Curve (NKPC). Increased competition among firms, however, increases price flexibility in the former, and has either no effect or decreases price flexibility in the latter. The effects of mark-up shocks on inflation and output are small when firms' price-setting behaviour incorporates concerns about potential loss of market share. These effects are further dampened in an environment of more intense competition. Under the assumption of increased competition, both models lead to unambiguous predictions about the direction of change in the slope of the Phillips curve. Rolling estimates of the NKPC indicate that the slope has declined or flattened for several countries since the 1990s. This evidence is consistent with the prediction of the Calvo model.