At Bangor there is an extensive tradition of empirical research addressing the long standing public-policy concern of balancing banking sector market power with regulation. The impact of Professor Molyneux’s research during 2008-2013 has been to inform policy formulation surrounding the debate about bank monopoly behaviour and its links to industry efficiency. In particular, his empirical analysis has focused on the use of non-structural (price-cost or/and price-revenue relationships) and structural (concentration ratio) measures of competition (and their links to cost and profit efficiency and various risks). Evidence of the impact and scope of this research is found in the extensive use of these measures in publications by, and policy debate within, a variety of financial organizations at the national, European and international level.