In this study, we investigate how two crucial political institutions – the electoral system and the intraparty candidate selection method – incentivise elite personalistic campaigning behaviour. We offer two contributions. First, we show the interactive effect of the two institutions on elite behaviour in campaigns, unlike most of the extant literature that focuses on parliamentary activity. Second, we apply the distinction between leader-focused (centralised) and individual-focused (decentralised) personalism to candidate selection methods. We argue that selection methods dominated by the party leader and ones employing primaries, two types of selection methods usually seen as opposites on established scales of candidate selection, are actually similar in their effect on politicians' personalistic behaviour during electoral campaigns. Using a dataset combining candidate surveys and expert coding of party selection rules, we analyse 9320 candidate responses from 101 parties across 16 democracies. We demonstrate that primaries-based selection methods correlate with more personalistic behaviour than collegial selection methods under party-centred electoral systems but with less personalistic behaviour in the most candidate-centred electoral systems. Leader-dominated selection methods similarly correlate with more personalistic behaviour than collegial ones only in closed-list PR systems, while their effect is insignificant in more candidate-centred systems. Our findings have wide-ranging implications. They call into question the conventional conceptualisation of candidate selection methods and their effect on politicians' behaviour. They also refine the scope of intraparty institutions' impact, limiting it to party-centred electoral systems. Conversely, our findings serve as a reminder that students of electoral systems investigating their effects on elite behaviour must, at least in party-centred electoral systems, take intraparty institutions into consideration.
