We formulate two empirical tests for collusive behavior based on the theoretical insights of Werden and Froeb [1994] and Athey, Bagwell, and Sanchirico [2004]. The first predicts that colluding firms will reduce pair-wise differences in prices within a market if demand satisfies certain...

We study the effect of consolidation on airline network connectivity using three measures of centrality from graph theory: Degree, Closeness, and Betweenness. Changes in these measures from 1990 to 2015 imply: i) the average airport services a greater proportion of possible routes, ii) the...