Electoral systems vary widely in the degree to which they encourage candidate-centric or party-centric patterns of competition. For example, some allow voters to choose among candidates from a single party, while others allow no such choice; some are used to elect individuals while others elect slates of individuals. We hypothesize that changes in electoral systems in recent decades should trend towards candidate-centrism and away from party-centrism – a process that we label ‘personalization’. We base this hypothesis upon the widespread phenomenon – charted, for example, by Russell Dalton – that voters are becoming disengaged from and distrustful of political parties. Assessment of this hypothesis requires first that we clarify the concept of personalization, second that we develop our understanding of how various aspects of electoral systems affect personalization, and third that we gather empirical evidence on electoral reforms that increase or reduce personalization. We pursue each of these steps. Our empirical evidence is based on a new database of electoral reform in Europe since 1945.