Population Growth and Decline

I think population cycles and patterns are interesting because it is an effect of past circumstances and proceeds to influence the future. For example, the baby boom that occurred after surviving soldiers of WWII came home and got married. One would think that once all the baby-boomers got old enough to have children there would be another dramatic rise in population, but it doesn't necessarily work like that. Now, there is a baby "bust". Women are having fewer children because they are marrying later and choosing to work. And it's not right or wrong, but I wonder what the long term consequences will be (they will certainly be affecting me!). If the decline continues, there will a smaller ratio of working age people to retired people relying on social security and such. Will people, and not just in my generation, but my parents' generation, have to work longer? Another thought is that the planet may not really need more people on it right now--more people requiring water, using energy, taking up space...Just a thought. I don't think people should stop having kids!
Another fascinating aspect of population are the effects of gender ratios. There was recently an article in The Economist about "China's missing baby girls". In China, (and also northern India) girls are, basically, not desired, and mainly because they provide no economic benefit to their families. Girls are either aborted, killed, or abandoned. Orphanages are filled with girls, and they are still neglected. Anyhow, the skewed gender ratios are problematic for men who want to get married but can't find a wife. One, now they can't have children, and they are literally called "broken branches". This also results in men smuggling/trafficking brides from nearby countries like India, Nepal, Vietname, etc. There is a rise in violent crime...think: lots of men with no outlet for their testosterone. Basically, women, and thus girls, are necessary for maintaining a normal and healthy population cycle. And also, those parents need to understand how smart and capable and beautiful their daughter could be!