Juku, Yobiko, Dersane, Crammers, coaching institutes or tuition class, call them what you will but all these describe the same phenomenon - of studies outside the mainstream education system. In India, it's almost like the neighbourhood shop, making it seems like something that is unique to our country. But it's not.

Its prevalence is apparent across the globe, seen in low-income countries like Cambodia and Kenya, and also in more prosperous ones like Japan and Canada. Private tutoring has become so much a part of the educational environment worldwide that its existence is barely ever questioned. Rather it is considered a necessity.

A big enterprise, like in India, it employs thousands of people and consumes large amounts of money. Despite this, its unregulated and informal character makes it difficult to get data on its shape and size in most countries.

However, some scattered data across regions is available through studies and has been put together in a cross-national study by UNESCO's International Institute for Educational Planning. Educationist Mark Bray, the man behind the study and now director, Comparative Education Research Centre at the University of Hong Kong, took the process further in his book Confronting the Shadow Education System. The data in the studies, though, is restricted to school-level education.

The overall picture that emerges is interesting. In Mauritius, almost all senior secondary students receive tutoring;in Japan, 70 per cent of students start taking tuitions by the end of middle school. In Malaysia, 83 per cent of the children get tutoring by the time they get to the senior secondary stage.

The size of the coaching institutes varies widely. Japan, for example, has many modest-size tutoring centers, but there are also players who have expanded worldwide. Kumon Educational Institute, which specialises in teaching math and English in innovative ways, has become a multi-national corporation and operates in 27 countries. Nine juku (private tuition) firms are listed on the Japanese stock exchange. Interestingly, there is an overall increase in tutoring activity in Japan even though the country is witnessing a fall in birth rates.

While supplementary tutoring can be found in almost all parts of the world, it is more prevalent in Asia, Africa, Eastern Europe and Latin America. The regions where tutoring is not quite as popular are Western Europe, North America and Australasia. The practice is extensive in cultures that stress on diligence and effort in contrast to those which emphasise ability. Differentials in living standards of people with different levels of education are also an indicator. In societies where these differentials are higher, like Singapore or Hong Kong, people are willing to pay a higher premium to achieve that extra. It is not so in countries like the UK and Australia where this differential is less marked.

But increasing competition has heralded change everywhere. The US has seen a rapid expansion of the shadow education system under the No Child Left Behind Act (2002), under which the state is mandated to provide supplemental education services to schools that fail to make adequate progress for three consecutive years. In 2006-07, 3. 3 million students were eligible for supplemental educational services, a six-fold increase since 2002-03 according to the US Department of Education. In Canada, a study found that about 24 per cent of Ontario parents with school-aged children hired tutors in 2002, and the tutoring business has grown between 200 and 500 per cent in major Canadian cities over the past 30 years.

The subject most fueling this expansion is, yes, mathematics. Analyses of the data of the Third International Mathematics and Science Study (TIMSS) showed that a substantial amount of shadow education in mathematics existed all over the world. It found high rates of participation in Columbia, Slovakia and the Philippines, and appreciable rates of 10-20 per cent in some European countries without much of a tradition in shadow education, such as Norway, Germany, Sweden, France and Holland.

As the parallel education industry spreads its tentacles all over the planet, the debate that's raging is whether it should be banned or regulated. Bray says it's important that governments don't stay blind to its existence and confront it instead. "The governments should actively look at shadow education, " he told TOI-Crest from Hong Kong. However, he cautioned that blanket prohibition would not work. "This has been tried in various places - Korea, Cambodia, Myanmar - but has always failed, " he says. But most of all, governments should improve the mainstream education system so that shadow education becomes redundant.