Imagine being a manufacturer of a product that nearly three members out of 10 in the target audience are unable to do much of anything with.

Printers inadvertently fit that description because of a widespread learning deficit called functional illiteracy—a disruptive and costly social phenomenon that is only getting worse.

People categorized as functionally illiterate can make little practical use of language in visual form. This means, for example, that they can’t fully grasp the meaning of printed words in anything more complex than brief sentences or simple signage.

As individuals, they lag far behind others in terms of employability and earning growth. In communities where functional illiteracy is prevalent, public safety and health and quality of life are likely to be compromised.

Functional illiteracy isn’t a character flaw to be denigrated—it’s a societal failure that tarnishes everyone with its negative outcomes. If anything about functional illiteracy is open to criticism, it’s how much less public attention it gets than a problem of its magnitude ought to receive.

The most substantive data on functional illiteracy come from the Program for the International Assessment of Adult Competencies (PIAAC), a study of adult cognitive skills and life experiences developed by the Organization for Economic Cooperation and Development (OECD) and conducted in the United States by the National Center for Education Statistics (NCES).

PIAAC assesses the skills of working age adults (ages 16 to 65) in the domains of literacy, numeracy, and adaptive problem solving. It tracks literacy across three categories of reading ability:

• Level 1, the lowest, comprises adults who can be considered at risk for difficulties using or comprehending print material. At best, they can perform simple tasks such as filling out short forms, but drawing inferences or combining multiple sources of text may be too difficult. Some adults below Level 1 may be functionally illiterate.
• Level 2 adults can read print and digital text, make simple inferences and comparisons, and navigate to key information in a digital environment. But more complex inferencing and evaluation with text-based documents may be too difficult for them.
• Level 3 readers have literacy skills that let them understand, interpret, and synthesize information across multiple, complex texts. They can evaluate the reliability of their written sources and infer sophisticated meanings and complex ideas from them.

PIAAC completed its most recent round of data collection between August 2022 and June 2023. The data revealed that from 2017 and 2023, overall average scores for U.S. adults declined in literacy and numeracy. This was evident in increases in the percentages of adults performing at the lowest level of proficiency, Level 1 or below, in both literacy and numeracy.

In literacy, the percentage at Level 1 or below increased from 19 to 28%. The increases were seen for both employed U.S. adults across all self-reported employment categories as well as for those out of the labor force…