The state subsidy intended to help poor families take better care of their children has not reached its 30% target, according to the Thailand Research and Development Institute (TDRI).
This has prompted calls for the subsidy, which currently offers financial help to babies and toddlers of poor families, to be extended to every baby and toddler in the country.
Somchai Jitsuchon, research director of Inclusive Development at the TDRI, said the institute has found "exclusion errors" in the handing out of the subsidy where those entitled to the financial help, about 100,000 babies and toddlers, are not getting the money.
Many failed to receive the subsidy because they thought applying for the money involved a tedious process, they had no time to apply, they did not have all the necessary documents, or they were unsure if they were entitled. However, the TDRI has surveyed 5,700 people in nine provinces with a large population of poor residents and found that only 2% of them did not know about the programme.
At the launch of the subsidy in 2015, 400 baht a month was distributed to the parents of newborns and babies aged up to one year old. The fund was later expanded, from newborns to three-year-olds and the subsidy increased to 600 baht a month.
However, the targets, the babies and toddlers of poor families, remained the same.
Mr Somchai said the system has been abused as some recipients are not from poor families. "This kind of abuse [the rich obtaining the money] is more damaging than the poor not getting the subsidy," he said.
Michael Samson, of the Economics Policy and Research Institute, said the fund not reaching the 30% target is a high figure, which is worrying.
It means tens of thousands of babies and toddlers may be deprived of money needed to buy nutritious food essential for their long-term growth and development, he warned.
However, he said it was hard to disburse the subsidy and make sure the parents of every entitled baby and toddler have access to the money. There are difficulties in terms of intensifying the family screening process and recruiting more officials to conduct the screening.
The best solution would be to stop subsidising only poor families and expand the fund to cover all babies and toddlers, he said.
"This way, there will be no failure or shortcomings in getting the subsidy across, even to the poor," Mr Samson said.
Mr Somchai, meanwhile, said the expanded coverage would not put much of a financial burden on the government, costing only about 0.2% of gross domestic product.
It would be worth investing, he said, in the early development of children. "Letting 100,000 or so babies and toddlers go without the vital nutrition they need would be a loss to society," he said.
Seelada Sangsikumphum, manager of the Foundation for Slum Child Care, said 600 baht a month may not seem a lot to some people. However, it has been a crucial factor changing the minds of many teenage single mothers who might otherwise have decided to abandon their newborn babies.