Opinions on population growth generally fall into two groups. Some people say "the more the merrier." They favor continued - and indeed unlimited - population growth because a growing population helps to drive economic growth and provides an ever-larger number of taxpayers, workers, and consumers. Others say "the fewer the better." They favor low population growth or even decline because a large and growing human population inevitably stresses the environment and because excessive immigration leads to cultural fragmentation.
I generally support the position of the fewer the better. Indeed, relying on endless population growth to generate economic growth and provide an ever-larger number of workers and taxpayers to support retirement programs like social security and medicare seems to me to be nothing more than a pyramid scheme. Like all pyramid schemes, the system inevitably must fail. The only question is when - while population is still relatively reasonable, or not until that population reaches a level seen only in dystopian science fiction?
In The Empty Cradle, Phillip Longman argues for the other side. However, this book still fills a worthwhile niche. Population growth and demographics tend to be overlooked in day-to-day debate despite the enormous long-term implications of these subjects. Longman performs a valuable service by bring attention to these issues.
The Empty Cradle was published in 2004, which limits its its topicality. Much has changed since then. Most importantly, China's population has reached the point of zero growth, and may actually be declining. (Deficiencies in the statistical information provided by the Chinese government make the answer somewhat unclear.) The Chinese government has responded by eliminating its one-child rule and seeking to encourage its citizens to have more children; the effect, if any, these changes will have is an open but important question. Also, although India's population continues to grow, its birthrate has declined to the long-term replacement rate of 2.1 children per woman. Due to rapid demographic changes such as these, the subject of population growth can be addressed best in monographs, which can be published in a continuous series, rather than a book which can include more detail but cannot address new developments.