Why a VAT hike will hit the poor hardest 

I agree with most of the suggestions made by the economists interviewed for your article. However, one suggestion is clearly based on a serious misconception. That is the notion that a VAT hike from 7 per cent to 10 per cent would not hit the poor hardest. This is premised on the fact that the rich on a per capita basis pay a disproportionately large share of the total VAT collected, due to their vast spending power. However, this fact is irrelevant in this context.  The wealthy also save and invest a large part of their incomes without the need to pay VAT, as well as spend it on overseas trips and education for their children, generating sales tax for other countries.
None of this can be done by the poor. Instead they spend all of their income on goods and services, nearly all of which are liable for Thai VAT. Since the poor obviously pay a far higher percentage of their incomes to the government in the form of VAT, it stands to reason that they will be hit hardest by a VAT hike, rather than the rich who pay a much lower percentage of their incomes in VAT and will comfortably absorb a VAT hike.
George Morgan
Bangkok