To some observers, juku represent an attempt by parents to exercise a meaningful measure of choice in Japanese education, particularly for children attending public schools. Because of the commercial nature of most juku, some critics argue that they have profit rather than education at heart. Shares in five juku chains are traded publicly, and 25 others were as of 1992 ready to issue stock as well. Not all students can afford to attend juku, but school and university test scores rise in direct proportion to spending on juku. The average fee is $160 a month for elementary school and $175 a month for junior high school, but the best ones are several times that amount. Japan spent $10.9 billion on tutoring and cram schools in 1991 alone, including $9 billion on juku for students in the ninth grade or below "almost double the figure spent [in 1985]." With poor students therefore at risk of falling behind, the social and economic inequality in what had been a relatively egalitarian approach to education, at least in public schools through ninth grade, is why Japan's powerful teachers' union does not support the juku institution. In response to these accusations,  "juku teachers and administrators say that since their schools are profit-making enterprises, they have to guarantee results to succeed. The results are easy to measure since they depend on how many graduates pass the examinations for private school. The profit motive, in other words, provides an incentive to create an atmosphere in which students want to learn." "The rise of juku is praised as a secret of Japanese success, a healthy reflection of a system of advancement based on merit. It is also criticized as forcing a new generation to surrender its childhood out of an obsession with status and getting ahead. 'Juku are harmful to Japanese education and to children,' said Ikuo Amano, professor of sociology at the University of Tokyo. 'It's not healthy for kids to have so little free time. It is not healthy to become completely caught up in competition and status at such a young age.'" For some, "the schools are also seen as reinforcing a tradition of rote learning over ingenuity." In many ways, juku compensate for the formal education system's inability or unwillingness to address particular individual problems. "In a 2008 government survey, two-thirds of parents attributed the growing role of juku to shortcomings in public education," such as the abolition of Saturday schooling (which therefore reduces the number of hours available to cover course material) and the reduction of curricular content (see Yutori education).