The main problem is that all children have to pay fees, even in state schools. Primary schoolchildren in the Jakarta area pay around 5,000 rupiah (about 30p) a month in fees, roughly the price of a kilo of rice. Even this is too much for parents who may have to feed several children on as little as 3,000 rupiah a day.
"The most important thing is that we eat. If we have money left, it's for school," says Hayadi bin Yazin, an unemployed bus driver who lives in a row of one-room wooden houses in a western suburb of the capital.
In the crowded west Jakarta district of Tambora, local education chief Sri Panini says there has not yet been a calamitous fall in attendance rates since term began in July, but the pain is starting to show. "Out of every hundred children, maybe 75 can pay," she says. "We let the others pay half or go free. As part of the government, we have to help them."
Teachers at five other schools in or around the Indonesian capital all echoed this attitude. Typically, 5 to 10 per cent of their pupils have fallen behind with their fees. But they say they will keep them in school, finding private donors where possible.
"The general feeling is that it's going to be hard for parents," says Basilius Bengoteku, an education official with the World Bank, which is leading a Pounds 195 million programme to subsidise fees.
He says schools are reluctant to kick out children for being poor, but the parents often stop sending them out of a sense of shame. He and his colleagues are about to start flying around the country to find out what is happening in schools. They appear politely sceptical, however, about government claims that up to 20 per cent of pupils have dropped out.
In some pockets of this vast country, people are doing quite well because of high world prices for cash crops such as pepper. In other parts,including Jakarta, people are losing their jobs by the thousand.
There are fears that the government's efforts to tell people about the fees subsidy programme are not working. No teachers in Jakarta seemed to know that there were two schemes, one for individual pupils and one for schools.
Some of the poor children are more vulnerable than others, especially recent immigrants from the countryside or children whose fathers have died.A cruel feature of Indonesia's education system is that at secondary level, limited places at state schools tend to go to those whose parents are articulate or well-connected. The very poorest are forced to send their children to private schools which cost more even though they offer an inferior education.
Rahmat, 15, dropped out of a private high school because he could not afford an examination fee of 12,000 rupiah. "I like religion and mathematics," he says. Instead, he makes Rp 4,000 a day cleaning cars.