This paper will begin with an overview of the concept of illiteracy, as well as its main individual, intergenerational, social, and economic consequences, in order to establish a comprehensive analytical framework. A methodology will then be proposed to estimate the employment and income gaps which illiteracy generates, using three case studies as examples: Ecuador, The Dominican Republic, and the Brazilian state of São Paulo. The final section of the document offers a number of conclusions, as well as a discussion of future challenges.