What are the consequences of low literacy rates?

Unemployment is one of the many consequences of Illiteracy

When one is illiterate, he is unable to be proficient in reading and writing, thus having limited ability to obtain and understand essential information. 

The current workforce demands workers fully capable of registering information, hence the inability to do so would result with many harmful economical effects. An illiterate may be having lower income, lower quality jobs, and worst, he might be unemployed if he does not meet the required job skills. Illiteracy causes one to have reduced access to lifelong learning and professional development.

Personal health is also directly affected by illiteracy. When one could not communicate well, he would have a low self esteem, often leading to isolation. Illiterate individuals have more workplace accidents, take longer to recover and more often misuse medication through ignorance of health care resources and because they have trouble reading and understanding the relevant information (warnings, dosage, contraindications, etc.).

Societies are also affected by illiteracy. Literacy is essential for states to be competitive in the new global knowledge economy. The higher the proportion of adults with low literacy proficiency is, the slower the overall long-term GDP(Gross domestic product) growth rate is, the lower the level of community involvement and civic participation. Illiteracy is also a main factor of poverty in many countries.

Therefore, individuals without an adequate level of literacy could not be on a completely equal basis in social and political discourse.
 
Source:  http://www.fondationalphabetisation.org/en/adults/illiteracy_literacy/consequences/