Global Comparison of Reading Volume
According to the NOP World Culture Score Index, weekly reading hours are highest in India (10.7 hours), Thailand (9.4 hours), and China (8.0 hours), while South Korea (3.1 hours) and Japan (4.1 hours) rank near the bottom. Japan's Agency for Cultural Affairs reported in 2023 that 47.3% of Japanese adults "did not read a single book in the past month," a figure essentially unchanged from 46.1% in 2008.
However, the definition of "reading" varies across surveys. Whether e-books, audiobooks, and web articles are included dramatically changes the numbers. Pew Research Center (2023) reports that 75% of US adults "read a book in some format in the past year," dropping to 62% when restricted to print. Media diversification has made international comparison of "reading volume" increasingly difficult to standardize.
Reading and Cognitive Function
Wilson et al. (2013) at Rush University demonstrated in a 6-year longitudinal study that older adults with high levels of cognitive activity including reading experienced 32% slower cognitive decline. However, this does not prove causation; reverse causality - that people with higher cognitive function are more inclined to read - cannot be excluded.
Meanwhile, the type of reading matters. Kidd & Castano (2013) experimentally showed that reading literary fiction improves "theory of mind" (the ability to infer others' mental states). Nonfiction and popular fiction did not produce the same effect. Not just how much one reads but what one reads influences cognitive outcomes.
The Opportunity Cost of Reading Time
Reading time competes directly with other activities. Since the proliferation of smartphones, the battle for "spare moments" has intensified, with reading now competing against social media, video, and games. According to the US Bureau of Labor Statistics, average daily reading time for those 15 and older declined from 21 minutes in 2004 to 15 minutes in 2022.
Yet total information consumption has increased. The decline in reading time may be better interpreted as "the medium changed" rather than "people stopped reading." Whether the ability to deeply engage with long-form text (deep reading) and the ability to rapidly scan short web content are substitutable skills remains an open question.
The Correlation Between Reading and Income
Multiple surveys report a positive correlation between reading volume and income. Pew Research's 2023 data shows 86% of Americans earning over $75,000 read a book in the past year, compared to 64% of those earning under $30,000. In Japan, those earning over 10 million yen read an average of 3.2 books per month versus 1.1 books for those under 3 million yen (Rakuten Books 2022).
Interpreting this correlation requires caution. It does not establish that "reading increases income." Rather, higher earners have more time and financial resources, higher education levels, and environments conducive to reading - a common cause driving both variables. When comparing reading volumes in a ranking, ignoring this socioeconomic context risks the erroneous conclusion that "non-readers simply lack effort."
Practical Use of the Reading Ranking
Knowing where your reading volume falls globally can prompt reflection on reading habits. However, the number of books or hours matters less than what you gain from reading. Reading 100 books a year while retaining nothing is hollow; reading 5 books deeply and applying insights to action delivers substantial value.
The most effective way to build a reading habit is to lower the barrier to the absolute minimum. Start with "one page per day" and increase volume only after the habit is established. Behavioral science (BJ Fogg's Tiny Habits) demonstrates that small actions compounded over time produce major behavioral change. Rather than feeling overwhelmed by ranking numbers, focus on reading one more page than yesterday.