“…The upper-middle-income countries (defined as having per capita incomes from $4,126 to $12,735) include Colombia ($6,990), Macedonia ($4,870), and the Chinese province of Yunnan ($4,435). These countries represent several world regions: Eastern Europe and Central Asia (Armenia, Georgia, Macedonia, and Ukraine), Latin America (Bolivia and Colombia), Sub-Saharan 3 As Samuels et al (2015) acknowledges, the Grade R evaluation was not a randomized control trial. Since the program was already in place, researchers matched participant and nonparticipant students with similar characteristics.…”