Abstract
This chapter addresses the relationship between increased online chatting during 2000-2018 and changes in reading literacy. The findings relate to per-country changes and involve 39 countries from five continents. The data was derived from the international PISA surveys. Two groups of countries are distinguished: those with a low prevalence of online chatting in 2009 and accelerating growth during 2009-2018 and those with high chatting prevalence in 2009 but decreasing growth afterward. The first group shows substantially improved reading literacy during 2000-2009. However, this positive trend changed around in the subsequent period when online chatting clearly accelerated in these countries. In contrast, the second group shows improvement during 2009-2018, when the growth in online chatting decelerated in these countries. By 2009 the prevalence of online chatting was already high in these countries. This coincided with a small decrease in reading literacy. Additional analyses indicate that during 2000-2009 the relationship between increased online chatting and decreased reading literacy is mediated by changing percentages of students reading fiction at least once a month. During 2009-2108 the relationship is mediated by changing awareness of useful reading strategies.