The supplemental .zip archive for this publication contains the following files. 1. Stata program file to produce analytical sample from Costa Rica 1984 Census data Census1984_Sample.do Input data file of this program is available online at https://international.ipums.org/international/. Registration is required for accessing the data. 2. Stata program file to produce analytical sample from Costa Rica 2000 Census data Census2000_Sample.do Input data file of this program is available online at https://international.ipums.org/international/. Registration is required for accessing the data. 3. Stata program file to produce analytical sample from CRELES data CRELES_Sample.do Input data file of this program is available at http://www.creles.berkeley.edu/. Form submission is required for accessing the data. 4. Stata program file to produce final tables and graphs in Li, Dow & Rosero-Bixby (2014): The Declining Effect of Sibling Size on Children’s Education in Costa Rica Results.do This program takes the output data files from the first three programs as inputs.