The PISA studies of reading achievement of 15 year old students in OECD and partner nations show Anglophone nations to have continuing high proportions of weak readers (less than or equal to Level 2), with no improvement in this area from 2000 to 2006 (OECD, "Science competencies for tomorrow's world: Executive summary," 2007). The nations which have decreased their proportions of low achievers all use highly regular (transparent) orthographies, which expedite the development of efficient reading and writing skills (Galletly and Knight, "Aust J Learn Disabil" 9(4):4-11, 2004). While international scrutiny is being focussed on socio-cultural differences in education as a basis of nations' achievement differences, little consideration is currently being applied to the speed of reading accuracy and spelling development. This is surprising, given the volume of research showing that orthographic regularity significantly expedites development of reading--accuracy and spelling--with very low rates of reading difficulties in nations with highly regular orthographies (Seymour et al., "Br J Psychol" 94:143-174, 2003, p. 174; Share, "Psychol Bull" 134(4):584-615,2008, p. 615). This paper proposes Transition-from-early-to-sophisticated-literacy (TESL) as a variable for use when considering cross-national achievement differences. It is proposed that Complex TESL nations (including Anglophone nations) will need paradigmatically different mechanisms to those used by Resolved and Facilitated TESL nations, for improved literacy and academic outcomes by lower achievers.