Japan has been a pioneer in the provision of this type of supplementary education. Private tutoring has long been a huge commercial industry in Japan, with annual revenues reaching an estimated US$14 billion by the mid-1990s. Nine private tutoring schools were already listed on the Japanese stock exchange at that time, and the tutoring sector had become a “crucial component of Japanese education” (Russell, 1997). Many students use school vacations, including the important New Year’s holiday, for intensive tutoring programs. To stimulate “school” spirit, several private tutoring schools—or _juku_ —have even had their students wear a kind of white headbands once worn in battle by _samurai_ warriors (Rohlen, 1980). The proportion of college students who have spent additional years after high school graduation to cram for college entrance examinations, often at specialized private tutoring classes, averages about 30 percent. For those who end up enrolling at the most highly ranked schools, the share may exceed 60 percent (Ono, 2007).<sup>4</sup> But recent research has made it clear that Japan is not unique in supporting a large and vibrant private tutoring industry. Tutoring is now widespread in many parts of the world, including the developing countries on which we focus in this paper. Table 1, which is largely based on Table II.1 in Dang (2007a), shows evidence on the extent of private tutoring in selected countries with a focus on developing countries. Although the studies cited there vary somewhat in methodologies and populations surveyed, certain patterns are clear.

First, while the incidence appears to be highest in East Asian countries, private tutoring is now an important phenomenon in many countries of different size, level of economic development, political institutions, or geographical locations. In some cases, spending on private tutoring approaches the level of spending on the formal public system. In Korea, households spent 2.9 percent of GDP on private tutoring in 1998, almost equaling the 3.4 percent of GDP spent on education by the public sector (Kim and Lee, 2004). A similar situation happens in Turkey, where the corresponding figures are 1.44 percent of GDP for private tutoring and 2 percent for public education expenditures (Tansel and Bircan, 2006).

Second, private tutoring is an important phenomenon not only for upper-secondary students preparing for university exams, but also for students at the primary and lower secondary levels, and sometimes (as in Japan) even among upper-secondary graduates.

Third, the private tutoring industry appears to be growing in many countries, both in absolute terms and relative to the formal education sector. Table 1 includes evidence of growth in terms of the percentage of students taking tutoring (in Kenya and Mauritius) and the number of private tutoring firms catering to them (in Turkey and Canada).<sup>5</sup> Evidence on tutoring expenditures, where it is available, also supports the notion that the sector is growing, as in Korea, where household spending as a share of GDP on private tutoring rose continuously from 0.7 percent of GDP in 1977 to 1.2 in 1990 and 2.9 in 1998. Finally, anecdotal reports also suggest an expansion in tutoring elsewhere; for 3