We extend the multiple jobholder literature by introducing the concepts of integration and leader-member exchange (LMX) to the multiple jobholding experience. Specifically, we seek to understand the extent to which supervisory relationships across jobs influence multiple jobholders to merge or blend their jobs such that they think about or attend to the job in which they are not physically present (i.e., integration). We draw from boundary theory to demonstrate why multiple jobholders may experience integration, which subsequently affects levels of sustained work engagement. We test our hypotheses using polynomial regression and surface plot analysis in a field study of 152 multiple jobholders from a variety of industries. We find general support for our theoretical model in that multiple jobholders with congruent LMX relationships (high/high or low/low) across jobs are more likely to experience integration (merging the primary job into the second job, but not vice versa) compared to multiple jobholders with incongruent LMX relationships (high/low) across jobs. Theoretical and practical implications are discussed.
