Naim Bro, Juan Pablo Luna
The link between descriptive and substantive representation is well established in the literature but is hard to trace historically, where class records are thin. We introduce a replicable enduring-elite surname measure, pairing a contemporary socioeconomic criterion with historical elite registers, and apply it across the Chilean Congress, 1834-2020. Against a dynamic population reference built from 22.65 million birth registrations, the enduring-elite share of Congress falls from about half in the 1860s to about 12% in the 2010s, with a sharp drop of 11 to 13 points around the 1925 constitutional reform. In 1910-1950, composition co-moves with the legislative agenda, net of party: common-surname legislators emphasize labor foremost, elite legislators a statecraft agenda of defense, foreign affairs, and administration. Across this window, who sits in Congress moves together with what Congress attends to.