But here is the problem:

Whatever choices women make at work and in life, those choices are easier if they delay child-bearing. Having a kid while you are a still a teenager can seriously curtail your options. Which is why it is good news that American teen-pregnancy rates are at historic lows! The rate of teen pregnancy has been falling since 1991 and dropped again dramatically in the last four years.
So, I must ask, why in the world, as the crisis is abating and fewer teens are facing the challenges of early child-rearing would the city of New York spend $400,000 on a campaign to publicly shame teen parents? That’s why this week’s letter goes to the man who signed off on that campaign.
An image of the ad is here. In the way I admire Robert Moses for being a master builder, I admire Bloomberg for being a muscular social engineer. But Moses built horrible expressways, and Bloomberg often makes mistakes. Teen pregnancy is actually on the decline; leave that matter alone. But what is on the increase?
A government report released on Wednesday shows pregnancy rates among women in their early 20s falling nearly 18 percent from 1990 to 2008. But pregnancies among older women rose far more dramatically: rates for women ages 40 to 44 went up nearly 65 percent. There were just 11.4 pregnancies per 1,000 women in that age group in 1990, compared with 18.8 in 2008.
This is what Bloomberg should be really addressing. Science has made what was once rare very common—middle-age pregnancy. Because humans as a whole should be making less babies, it's not at all good news that older women are now "picking up the slack." If babies are to be made, it makes more sense and seems more fair that it should be the business of younger women. Instead of shaming teenagers, Bloomberg should be shaming middle-aged women. The more rational and social thing for them to do is not contribute to the overflowing human pool but absorb the surplus—adopt a child.