Answers:
1. A 'sudden' imbalance: We did see a sudden imbalance in the West (though certainly not 3 or 4 to 1) during WW2, when so many men went off to the war. The result was women entering the workplace in unprecedented numbers, and in traditionally male jobs, 'Rosie the Riveter' being the archetype. That is already the case in Thailand, and it's not hard to find women working on road crews, construction sites, etc. I tried to find the reference for this, but I remember reading of European visitors commenting on the number of women working in what they considered traditionally male jobs long ago. I think it was in "Thailand: A Short History".
In America at least, this change in the workforce may have contributed to the women's lib movement.
2. Whether the imbalance is real or merely perceived, one of the obvious effects would seem to be that a man having multiple wives would not be too rare, whereas a woman having multiple husbands would be. That is polygamy would be more common than polyandry. The exception here would be bar girls who may have a Thai husband or boyfriend as well as one or more foreign sponsors. 'Mia noi' and 'baan lek' are pretty common terms in Thai and represent recognized relationships, not merely promiscuity. (I did offer to become one lady's 'sami noi' because she gave such good massages.

)
Another effect might be that we would see many women in the workplace doing man's work because there aren't enough men to do it.
One more effect might be that women would be willing to steal a man if they thought he wasn't too bad. The urge to mate is pretty strong.
3. I don't expect politicians to understand much except power and money.
4. Less promiscuity? More respect for women? More stability in relationships?
5. Anything that helps me understand the baffling behavior I see here is good. Even if Sarge is as wrong as possible, it's simply a fun, interesting thing to consider.
Comment:
Sarge and I began discussing this during his problems with the missus. I think it started from the simple remark that if things went totally wrong and they split, it certainly wouldn't be hard to find a woman to take care of him. This led to several fairly long discussions about demographics.
I first noticed an apparent imbalance in Phuket about three years ago, and attributed it to Phuket being a tourist area and women flocking there to work in hotels, restaurants, etc. as well as the bars. Kata, where I was staying, had a rather small bar area compared to Patong, so I wasn't really thinking about bar girls. It was also in Phuket that I first noticed female construction workers.
Here in Hua Hin I really hadn't paid much attention until we started discussing it. However, I had noticed that in my girlfriend's town in rural Ratchaburi there seemed to be a lot more women than men. Her extended family, and it is a rather large one, seems to have about two females for every male. That ratio holds for the six houses nearest the gf's mum's house. Most of those houses are owned by relatives. Most of the small pineapple processing plants around her home are owned by aunts or female cousins. She also seems to have a preponderance of female relatives elsewhere.
When I asked her about the ratio of men to women in Thailand her response was, "They say it's about seventy percent women." By 'they' she apparently meant the Thai government, but she has not produced a reference.
Here in Hua Hin is that I usually see more women than men, with ratios ranging from 1.25 to 1 to 4 to 1, but, in the case of one minibus ride, 9 men and 3 women. Actually getting an accurate count is difficult, so I only count people who pass a certain point I'm watching. Counting in Bintabaht is a bit silly, but actually yielded the lowest ratio of all, with Market Village yielding the highest. I didn't count girls in bars, only Thai people who walked past a certain point.
I just spent four days in my girlfriend's town and while I wouldn't think the ratio was even as high as 2 to 1, I certainly saw more women than men, including in the backs of trucks going off to work the fields or construction jobs, etc. About the only time I see more men than women is when I get together with buddies for a piss up or go to a police party - then it's almost 100% men, but I see those same guys in other places, usually with more women than men. I am hoping to take wide angle photographs at monk parties and other local celebrations that would be attended by a large percentage of the community. This would at least help me make a better estimate of the local demographic.
Her town is definitely not a tourist area. In many trips up there, I've only seen one other Westerner, and I've heard of one more. Until the coup and subsequent changes in price supports, bad global economy, etc. her area was comparatively affluent, so less people may have moved away to work.
If anyone wants to post numbers or estimates from upcountry, that is much more interesting to me than numbers from Hua Hin or any other tourist area. I expect to see more women here for the same reasons I did in Phuket - tourism.
While upcountry I asked four male Thai friends, "Are there more men or women in Thailand?" Three of the four answered 'women'. The fourth, the most rural, said he'd rarely been far from home so he couldn't speak for all of Thailand, but around home it seemed about even to him. I would canvass the entire town, but I don't have time and they already think I'm a little crazy. Canvassing the town would make them absolutely sure.
Spitfire certainly had some interesting comments in regards to the ratios within the educational system. Too bad my Thai isn't good enough to attend a university! Thanks for the information about primary and secondary schools. I just can't bring myself to lurk around a school counting kids.
I looked up the statistics after my first conversation with Sarge, so I'm not unaware of them, nor even concerned. I'm trying to talk to Thais to learn their perceptions of the ratio of men to women. If a majority of people believe that there are more available women than men, wouldn't that belief itself affect behavior? Certainly I have nowhere near a large enough sample at the moment to guess WHAT most Thais think about this, even in my gf's town.
Someone mentioned a possible imbalance between the numbers of potential mates. This may be the real 'issue', if you can call it that. Even a small imbalance, say 1.1 or 1.2 to 1 in the 20 - 40 age bracket would lead to a large number of single women. For me, it's less of an issue than simply something to look at, mostly for fun. And I get to watch a lot of girls!
The only figure I have for monks is from 1976 - then there were 213,175 monks not counting novices, and 10,529 nuns, according to a census quoted in "Inside Thai Society", by Niels Mulder.
Yeah, Sarge is a loon, but he's a fun loon, and I've spent many hours talking with him, usually sober. All he's done is take a set of observations regarding cultural differences, and another set of observations regarding the apparent ratio of males to females, and formed a hypothesis from those observations. At the very least, he is thinking about something that seems to be a big part of Thai life, and certainly of our lives here. How many board members who live here don't have a Thai wife or girlfriend? Is it really all just about money or could the woman in question not find a suitable Thai mate? How many board members have had a Thai woman, not a bargirl, make it obvious or state outright that she is available if you get tired of your wife/girlfriend or she doesn't take good care of you? I'm neither handsome nor wealthy, but it's happened to me more than once with women upcountry who speak no English and are 'friends' of my girlfriend. Nothing like that ever happened at home.
To make a long post endless, the Thai men I know are not very lazy. While you might see me sitting with friends around a concrete table having a few beers in the afternoon, it doesn't mean they never work. Several of my friends have more than one job, but still have a bit of extra time on an occasional afternoon. Wednesday afternoon when I went to visit a friend, he was studying law while his wife played cards.