In 1962, Spain implemented significant banking law changes to boost competition. This study investigates their impact on provincial banking concentration from 1964 to 1975, utilising novel provincial-level private bank balance sheet data and including savings banks. Results show a substantial decline in concentration across most provinces. Panel data models identify the determinants of banking concentration: larger populations and higher gross domestic product per capita correlate with lower concentration, while agrarian-focused provinces exhibit higher concentration. The provincial financial sector's structure also matters, with a higher number of branches and headquarters per capita associated with reduced banking concentration. These findings refine existing literature and provide new insights into the intricate relationship between banking concentration and regional economies in Spain.
