I have a piece up at the Atlantic called “What’s Really Behind the Ever-Rising Cost of Raising a Child in America“. You should go read (and comment) there.
To summarize: the cost of raising a child has increased substantially since 1960, but almost all of this increase is in areas such as education and health care designed to develop a child’s esteem and allow for self-actualization. At the same time, education and health care metrics have improved, and so have incomes. The cost of essentials such as food, clothing, and shelter have also seen substantial decrease. (Maslow’s pyramid is mentioned!)
The bottom line: parents in 2012 are able to spend less on keeping their child fed and safe and more on their child’s esteem and self-actualization. Even if other problems exist, where parents are allocating their resources is an unequivocal indication of Middle Class progress.