STEVE GOLDSTEIN: The birth rate in Arizona has taken a plunge over the past decade or so. Last year, there were nearly 81,000 births here while in 2007, there were about 103,000. The reasons are myriad, from economic concerns to immigration restrictions, and Lydia DePillis of CNN Money wrote a piece recently exploring them and why Arizona is such a dramatic example, and Lydia DePillis is with me. So Lydia, why was Arizona the focus of your story?

LYDIA DEPILLIS: Yeah, so whenever I see a big national trend happening, it's always fun to look at the extremes of that trend, and Arizona was that, for the drop in fertility over the last decade since about 2007. Its number of births and also its fertility rate have dropped more than any other state. That's partially because they were pretty elevated in 2007, sort of abnormally. So the number of births dropped over that period of time by 20 percent.

GOLDSTEIN: So my next natural question is, what are the reasons why?

DEPILLIS: It's some of the same reasons that the fertility rate is dropping overall nationally, except for those reasons are more pronounced in Arizona. So, take for example, obviously the recession. That really did a number on women's willingness to have kids or their ability to have kids because kids are expensive. In the economics literature, kids are talked about as a consumption good because you want them and you have to spend money on them. So you spend less money on them when you don't have as much. In Arizona, as I'm sure you guys know, there was a particularly large real estate crash, and so, many people were employed in the construction industry. Those jobs went away. People sometimes went away with them or people just chose to delay childbearing until they were on more steady economic footing. The other thing that is more extreme in Arizona than the national average is the percentage of immigrants, particularly from Mexico. Now I heard different stories about what was going on before the recession. Certainly, many people were coming to work in the tourism, hospitality, healthcare, construction industries. Foreign-born immigrant woman in Phoenix and all over Arizona had a higher birth rate than the state average and even the average in Mexico. What happened, as I'm sure you all remember, is in 2007, a law passed that required employers to verify someone's citizenship before employing them. So not only did many people leave or just not come, they also had fewer kids. Four years later, there was SB 1070. The other two things that were happening were increasing the availability of birth control and, starting around 2010, more funding from the federal government through the Affordable Care Act for sex education, contraception. So that's why, in Arizona and in other places, the biggest drop was in births to teen mothers.

GOLDSTEIN: What do economists say about the birth rate, either remaining steady or slowing down? Are there both pluses and minuses to that?

DEPILLIS: Absolutely. So the birth rate in America, just for some background, actually reached its lowest point in the 1970s after a big boom to more than three kids per woman in the 5'0s. That's the Baby Boom. So then the birth rate went back up during the 80s and 90s, reached around 2.2 or 2.3 in the mid-90s and then started declining again, and then really fell off a cliff after the recession. So that creates a problem because we have this enormous generation that is leaving their working years will need to be supported both through Social Security and in our health care systems. We don't have the manpower or the fiscal capacity to supply all those needs, especially if the generations coming behind them are shrinking and shrinking. So plenty of other societies have come upon this problem — Japan, South Korea — their birth rates are way lower than ours at the moment, and it's a real big challenge. But, economists also take note of the fact that when especially young mothers are having fewer kids, they are able themselves to stay in the workforce and invest more in the kids that they do have. So those kids have better outcomes educationally and career wise down the road, which is better for everybody, because if we have a higher productivity workforce, we need fewer workers. So there is a concern that this is going to be a big problem the U.S. will have to deal with. But, if we get past that baby boom and come to a slower growth point in our reproductive system, an equilibrium, that could be a good thing.

GOLDSTEIN: I wanted to ask you about one woman you have as part of the piece, specifically Crystal Cortez, who I think it was a really interesting dichotomy with her life, with having had a child at 17, but then, you talk about it really well in the piece, about how she has sort of changed her attitude. Can you talk more about her, please?

DEPILLIS: Yeah. Crystal is a wonderful young woman. She grew up in a conservative Catholic immigrant family who did not talk about sex at all. Her mother didn't actually have that many kids. She's one of two children, but many of her cousins have had more kids and her high school, her public high school as well, in Tucson didn't talk about birth control. It was an abstinence-only program so she had a steady boyfriend in her teens and ended up getting pregnant and decided to keep the baby, as many young women do. She doesn't regret that, but she did have the chance to get her education. She went to college and decided that one was going to be enough and then two would be a too big of a burden. The way she put it to me was also that, look, this is part of being a middle class American. You have fewer kids and that's a better financial choice, and she's no longer with the young man that she was with when she had her first child. She's now 27. But she says, you know, when I'm more stablely-partnered and I'm settled in my career, there's plenty of time to have another kid and that's all she wants.

GOLDSTEIN: Okay. Lydia DePillis is a senior reporter for CNN Money. Thanks very much for the time.

DEPILLIS: You're welcome.