A subset of research in the history of economics is organizational history – i.e. the study of the organizations producing, circulating and applying economic ideas. This article maintains that some research questions in organizational history call for quantitative methods because they ask about magnitudes. More precisely, we claim that quantitative methods should complement rather than replace other research methods when the research question is at least partly about magnitudes. We walk the walk with a study of one type of organization, central banks, and of its changing relationship with economic science. Our results point unambiguously toward a growing dominance of central banks in the specialized field of monetary economics. Central banks have swelling research armies, they publish a growing share of the articles in specialized scholarly journals, and these articles tend to have more impact today than the articles produced outside central banks.