“…Because such studies require more detailed information about leaders' personal background which is not covered by the Archigos, the majority of scholars have to undergo their own significant data-collection efforts pertaining to some aspect of leaders' personal background and traits. As a result, the new wave of leadership studies in political science and economics is extremely data-intensive (e.g., Alexiadou, 2015;Baturo, 2014;Byman & Pollack, 2001;Colgan, 2013;Dreher, Lein, Lamla, & Somogyi, 2009;Hayo & Neumeier, 2014;Horowitz & Stam, 2014;McDermott, 2007). While several new cross-national data sets have emerged that are able to account for various aspects of leaders' background and traits (e.g., Dreher et al, 2009;Ellis, Horowitz & Stam, 2015;Gerring, Oncel, Morrison, & Keefer, 2014;Ludwig, 2002), the majority of leadership studies focus, and provide data on, very specific aspects of leaders' personal background (e.g., Byman & Pollack, 2001;Horowitz & Stam, 2014); many only cover particular geographic regions or political regimes, e.g., only democracies or presidential regimes (e.g., Alexiadou, 2015;Baturo, 2014;Pérez-Liñán, 2009).…”