Nor is this difference due to New Zealand men moving to Australia, since there has been no change in the ratio of Kiwi men to women in Australia.
A lot depends on the woman, and while some Thai bar girls make excellent wives, many do not and are out for nothing more than money.
New Zealand men should make sure they know the girl well - and also her family - and are certain that her 'brother' or 'friend' is not a boyfriend or even a husband!
This is not the always the case, however, and the infamous Thai 'sin sod', or dowry, is frequently symbolic only.
It is often returned to the couple in whole or in part after the marriage ceremony.
Their assailants were described as European rather than New Zealanders, although accents mean little in a country open to immigration by people from all nationalities.
It is not only Thai women that are responsible for the imbalance between marriageable men and women in New Zealand, and figures show that other Asians such as Filipinos, and also European women have pushed this imbalance to 9% more women aged 30 to 34 than men.
Some experts have suggested that the shortage of marriageable men in New Zealand and the growing trend among New Zealand men to marry Thai women is leading to a tension between key groups of women in New Zealand and Thai women living the country.
The imbalance between young New Zealand women and marriageable is caused by a number of reasons, including work available and immigration policy, but it has led to cases of both verbal and physical abuse of Thai women.
There are many horror stories relating to Kiwis being tricked by Thai girls, but there are also many success stories.
The Buddhist temple in Christchurch is well attended by Thai women who have Kiwi or European husbands.
That is not the answer, and experts say that the problem relates to growing number of Asian and European females in New Zealand, not just Thai wives.