The research project evaluates second grade economic materials developed over a three-year period with Des Moines, Iowa, teachers enrolled in the Developmental Economic Education Program (DEEP). The study measured the effectiveness of student teacher materials in the teaching of basic economic understandings and an in-service program for teachers. The sample consisted of 24 teachers and 504 second graders. Three treatment groups included group one using the conventional social studies materials; group two using the specially designed economic education materials; and group three using the same materials as group two, but whose teachers had received in-service training. The five week study began with the administration of the SRA Test of General Ability (TOGA) and the Primary Test of Economic Understanding (PTEU) and ended with a second administration of the PTEU as a post-test. Conclusions are as follows: 1) Basic economic concepts can be taught at early elementary grades and growth in students' understanding of them can be measured; 2) A close relationship exists between materials provided for teachers and students and pupil growth in economic understanding; 3) Full-scale programs in economic education for teachers may not be necessary. Eleven recommendations are included in the report. (Author/RM)