Ph.D. training is an important mechanism for developing scientists who will serve our knowledge-based society. Because the quality of students who join Ph.D. programs significantly impacts the outcome of Ph.D. training, students' career choices at this initial stage--whether to proceed to Ph.D. or not--are of crucial interest. This study investigates how students' attributes and the local lab environment influence their career choices using a unique empirical design in the Japanese graduate education context. The results show that students with high scientific abilities are more likely to proceed to Ph.D., and that students are more likely to proceed to Ph.D. if the lab has a favorable local environment for research and for training. Importantly, the findings suggest that students' abilities and local environments interactively shape their career choices. In particular, high-ability students are drawn to local environments with high training capacities, whereas low-ability students are attracted to local environments with high research capacities.