The number of students at private tutorial schools preparing for entrance exams has dropped by about 20% over the past couple of years and the trend is likely to continue, putting many cram schools, especially small-sized ones, at risk of closing down.

Anusorn Siwakul, president of the Tutorial Schools Executives and Teachers Association, said a shrinking youth population and the economic downturn were key reasons for the decline, while online tutoring services are also grabbing a bigger piece of the pie worth 10 billion baht a year.

Mr Anusorn said that about 80,000 Thai students applied to sit the national university admissions exam in 2017, down from 100,000 the year before. There are just under 110,000 spaces available via the country's central university admission system this year, which is also down sharply from the more than 150,000 seats offered just two years ago.

"With lower numbers of students and the competition for university entrance growing less fierce, students nowadays don't need cram schools' services as much as previous generations did," he said.

Mr Anusorn said the downturn in economic activity has forced parents to be more careful with spending and be more selective in choosing which subjects their children take extra tuition for.

"The number of students attending math and English courses at cram schools is still at the same level. However the number of students enrolling in other subjects has dropped sharply. Parents only pay for what is necessary to their children," he said.

He said many students these days also choose to study with online tutors instead of attending bricks-and-mortar cram schools because it is cheaper and sometimes free of charge.

Mr Anusorn said these trends have dealt a blow to cram schools. Many have already started to reduce their branch number outside of Bangkok to control costs while others have closed down.

"Cram schools are now competing by launching promotions and reducing fees to attract students, so it is a tough market for small-sized players. We cannot expect to see classrooms overflowing with students like it used to be. We have no choice but to change with the times," he said.

Mr Anusorn, who also owns Wannasorn School, widely known as Pure Chem Centre (Chem Ou) which has 29 branches, said that in order to survive, cram schools need to focus on quality over quantity and rethink their strategies.

"I believe quality schools will survive no matter how tough the market gets," he said.