Dystopias are a nice favourite of mine in some sense. I'm not a dedicated fan nor even really a dilettante. What I mean is that if I read or watch a dystopia I generally like it. Some favourites in the genre are Watchmen, Jennifer Government, Brave New World and Children of Men (the film; I have not read the book). Today before the internet conked out I watched about half of What Happened to Monday.
The basic idea of this particular film is that a one child policy has been seen as the solution to a crisis of overpopulation. There is one enormous glaring problem with this idea however: overpopulation is a local condition. The reason a one child policy was pursued in China was because a geographically restricted state isn't able to leverage global systems. Thus it makes sense to limit population growth for a couple of decades. In a globalised world, such as the one in the opening montage of WHTM, especially one with a certain looseness for human dignity (basically all dystopias), efficient allocative measures are available. Food can be grown in one place and transported to another. It can be grown in all sorts of inventive ways. People can be housed in all sorts of inventive ways. People can be shifted out of overpopulated areas into regions that can have population. This latter notion is actually part of the early 20th Century demographic thought on the matter. In other words, it is probably the go-to solution.
Some of these ideas kind of come up when you're watching that montage. They talk about GMO food and how there have been all sorts of side-effects. This is unlikely. The truth about GMO food is that it is basically the only thing in the modern world where government shows a spine and regulates. And they regulate the crap out of GMO food. The chance of some kind of unexpected side effect arising from GMO is low... don't worry about it. Now I haven't seen all of the movie so this could be part of the plot rather than a flaw but even so. What I do know for sure is that WHTM takes a very food shortage angle on overpopulation... but still depicts the haves and the have nots. And, critically, both are commonplace.
If you're dealing with an issue of food shortage and have the political capital to operate the way the Child Allocation Bureau does there are much more intelligent responses than a one child policy: involuntary simplification... otherwise known as rationing. A lot of the literature on sustainability issues comes down to one main problem: consumerism... or "enough, is never enough". Now, I've got quite a lot of stuff myself (including two laptops) but a lot of this is because I don't throw stuff out, I just keep it all... as a result I actually don't have enough shoes and I wear 90% of my clothes within an 8 day period. With a dystopic big government you can make everyone me.
Dystopias can control how much stuff is owned and also how it is produced. It may not be the most economically, or at least financially, efficient way of doing things but to be honest I rather suspect Stalinist communism failed mostly because the whole world wasn't Stalinised so I can believe it is long-term possible. And even if this isn't so, you've got, what, 40-50 years or more to figure out a better system. But with food it's relatively easy. It's called rationing and the Western world did it in a big way during both world wars. With technology like that of WHTM you could get even more out of the system. You would simply have to have guards stopping people from cheating self-serve machines... the rationing system would be administered through their wristbands. Or something. As I said, the regime of WHTM is not pro-dignity.
The thing with dystopias is that they ultimately rise and fall on how realistic they seem. Jennifer Government and Brave New World are truly terrifying novels. Neither is very long but all the same both present societies highly plausible and very flawed evolutions of the world we know. Nineteen-Eighty Four is probably the most famous dystopia out there but it lacks this edge of "Dear God, I could see this happening"... when it was written this complaint was less true. Watchmen is obviously fantastic what with Doctor Manhattan running around both starkers and omnipotent (real gods wear clothes, dammit!), but it seems to operate on a plane where "could this happen" seems an unfair criterion. The also fantastic elements of Children of Men differ in that, unlike overpopulation, there is no immediately apparent lay explanation for why mass sterility couldn't occur. WHTM seems to me an entirely enjoyable film and I will finish it tomorrow, but it's not the world's best situation (even if the premise is quite delightful... not that I told you what it was).