Swelling household debt over the past nine years through 2018 can be largely attributed to debts run up by existing borrowers, while significant growth in personal, credit card and auto loans contributed to an uptick in the debt load last year, says the central bank's think tank.
Half of existing borrowers' increased debt during 2010-18 was the same type of loan extended by existing lenders, followed by new types of loans by new lenders and the same types of loans by new lenders, said Sommarat Chantarat, head of financial systems research at the Bank of Thailand's Puey Ungphakorn Institute for Economic Research (PIER).
Seeking a new type of loan from existing lenders only accounted for a small proportion, she said.
"Only one-fifth [of the increased debt] was the result of new borrowers," the report said.
According to a breakdown by loan type, personal loan and credit card growth was mainly driven by their existing borrowers, while the rise in mortgages largely stemmed from existing borrowers who had never had housing loan accounts and who sought mortgages from new financial institutions.
Unlike personal loans, credit cards and housing loans, half of the increased auto and motorcycle loans came from new borrowers.
Household debt picked up again to 78.6% of GDP at the end of 2018 from 78.3% in the previous year. Thais debt load peaked in 2015 at 81.2%.
PIER's report found that one-third of existing borrowers with higher debt borrowed from several financial institutions in the same year and that the ratio is on the rise.
Existing borrowers ran up more debt through personal loans, credit cards and auto loans, while most new borrowers had only one lending account, largely either personal or auto loan.
Moreover, the report said non-banks were the largest creditors of new borrowers, followed by specialised financial institutions and mid-sized commercial banks.
But debt accumulation of new borrowers in the same year was setting trends. More than 40% of existing borrowers who ran up debt owed to more than four lending accounts at the same time, and the figure continued to increase from 30% in 2010 to 45% last year.
"The research found that some of them held as many as 20 lending accounts, most of them credit card and personal loans," Ms Sommarat said.
She said the central bank's tightened unsecured loan regulations initially paid off in dampening new loan demand after their enactment in 2017, but personal loan demand became stronger again in 2018.
The report said half of new borrowers were young, and debtors aged below 25 were taking on debt at a high rate. The proportion of existing borrowers who are elderly also rose. Such trends suggest that Thais load up on debt at a younger age and owe it longer.
Mortgage borrowers aged below 35 represented 60% of loan applicants in 2018, up from 40% in 2010. Auto loan borrowers aged below 25 accounted for 15% last year, up from 5% in 2010.