Half a century after the “Second Great Debate” in international relations (IR) started, scholars still perceive the qualitative versus quantitative division as their principal divide, and yet we do not have a good grasp of the impact of this divide. My research explores how the divide shaped the incentives and behaviors of scholars and influenced the organization of our academic communities and knowledge production. The impact of the divide expressed itself in the distribution of research among methodologies in terms of relative quantity and impact. Less obviously, and yet more importantly, the divide influenced the distribution of quantitative research among different institution types, across fields and journals, and with respect to policy engagement. Using the TRIP database of 7,792 IR articles in twelve top journals from 1980 to 2014, I classify journal articles into three categories—quantitative-only, qualitative-only, and mixed-methods—and categorize author institutions into similar types—publishing quantitative research only, producing nonquantitative work only, and publishing various proportions of quantitative research. Notably, qualitative and quantitative works switched positions over time in terms of relative quantity and impact, with quantitative research more likely published but only slightly more cited in the recent decade. More importantly, the divide produced other less obvious but more serious outcomes. Among 1,111 institutions that ever published IR research in twelve top journals over thirty-five years, two-thirds published nonquantitative research only; fifty-three institutions published more than half of all quantitative articles; institutions publishing quantitative-only or nonquantitative-only research constituted two modal categories. Political science journals published more quantitative research, persistently and with growing convergence; IR journals also evolved toward publishing more quantitative research though with persistent divergence and forming two clusters. Quantitative articles and political science journals were significantly less engaged in providing policy prescriptions than qualitative articles and IR journals. To overcome this lasting and self-perpetuating divide, we must better understand its impact, learn to appreciate alternative approaches, and change the way we train future scholars.