There are different homework policies around the world. The Organization for Economic Cooperation and Development (OECD) keeps track of such policies and compares the amount of homework of students from different countries. For example, an average high school student in the US has to spend about 6 hours a day doing homework, while in Finland.
The amount of homework given does not necessarily affect students' attitudes towards homework and various other aspects of school. Epstein (1988) found a near-zero correlation between the amount of homework and parents' reports on how well their elementary school students behaved.