A study of over 3,000 U.S. high school students who took the Test of Economic Literacy (TEL) in 1986 reveals a lack of basic understanding in the four basic TEL concept clusters of fundamental economics, microeconomics, macroeconomics, and international economics. The TEL was administered pre- and posttest where students were enrolled in one of four types of courses: basic economics, "consumer economics," social studies with economics, and social studies without economics. Students in the economics courses did show significant improvement (+7.5 percent) after the TEL posttest examination while the others did not. Regression analysis was used to identify the effects of variables such as student background and environment or teacher and course preparation. Students in districts which participated in the Developmental Economic Education Program (DEEP) sponsored by the Joint Council on Economic Education scored higher than other students. The amount of college coursework in economics taken by the teachers themselves directly related to increased student performance in the classroom. A significant amount of ignorance was displayed in basic concepts and relationships in macroeconomics and international economics. Three tables of TEL data and 12 references are included in the report. (PPB)