Economic literacy is vital for functioning effectively in today's society. Consumers need to manage their finances, investors need to plan for their future, and voters need to choose among competing economic plans. As students move on to college or enter the workforce, their understanding of the economy will help them become financially responsible citizens. The National Assessment of Educational Progress (NAEP) monitors students' attainment of these skills and knowledge with its twelfth-grade economics assessment. First administered in 2006, the NAEP economics assessment measures twelfth-graders' understanding of a wide range of topics in three main content areas: market economy, national economy, and international economy. This report provides results of the economics assessment in 2012 based on a nationally representative sample of nearly 11,000 twelfth-graders. Results from 2012 are compared with those from 2006 to investigate whether the nation's high school seniors are becoming increasingly literate in economics. Percentage of students and average scores in NAEP economics at grade 12, by selected characteristics: 2006 and 2012 are appended. Technical notes are included. (Contains 17 figures and 4 tables.)