Time to interject my own personal opinion and observations.
Prior to the "Sexual Revolution", there was a large cultural bias against sex outside of the marriage, or at least the open acknowlegement of sex outside the marriage. Considering that prior to effective female birth control, any sex involving male and female sex organs imposed a moderately high risk of pregnacy. Also, prior to the "Sexual Revolution" interaction between unmarried males and females was, by today's standards, closely monitored, not only by the couples family, but by other members of society. Being caught in a compromising position had serious societal consequences, especially for the woman\girl. Having a child out of wedlock was a stigma for both the woman and the child concieved. Along with that however, there was the societal obligation on the part of the father of the child, to "do the right thing" and marry the woman whom he impregnated, take responsibility. His friends, family, and aquaintances would expect that of him.
With the introduction of effective birth control for women, for all practical purposes, we eliminated the need for persons to be careful whom they "slept" with. Other than the possible emotional entanglements, sex was no longer tied to any committment between the partners.
With the proper care taken, the odds are fairly fantastic that a woman can get pregnant by accident. Many women, especially the young, have forgotten the fears that women had at one time, of unwanted pregnacy, and without that fear, can, and have become somewhat blasé about taking the steps to ensure that pregnacy doesn't occur, i.e. the pill, or other female contreceptive, and or ensureing the male is wearing protection. So what we end up with is a girl\woman, who
accidently becomes pregnant.
Coupled with this, we have a society, at least in the West, that the stigma of having children outside of wedlock has diminished to the point of almost non-existance. No longer are there the whispers behind the back about being a tramp, etc., and no longer are the children ostracized (in this part, rightly so, since they had absolutely nothing to do with the manner of thier conception) because of the circumstances of thier birth.
Along with this, the work place has grown much more friendly for women, allowing a single mother a greater chance to be financially capable of raising a child without the presense of a man.
So now we have a society that no longer places the premiem on children being born only to those whom are married to each other, where the act of sex has become, at least within the mind, divorced from the reality of procreation, and the increased ability of women to "go it alone".
Also we have a popular culture, that has increasingly laughed at the presentation of the "Leave it to Beaver" type family, or even the "Cosby Show". Culture has gone from depicting a responsible man as one who has a job, takes care of his household, remains faithful to his marriage, and engaged with his community, and maybe, just possibly, religious, as
old fashioned, no longer a man of the times.
Pop culture hasn't helped any either, though I do see some improvement there in the last couple of years. Still, with VH1, MTV, BET, etc. depicting everything but committed relationships, I haven't exactly seen any huge push that marraige is anything other than something forced on two people, or something that only saps get themselves into.
All of these things, I believe, contribute to the overall increase in children born outside of marriage. And while I am certainly aware that women are no longer required to have a man around to financially support a child\children, I do have to ask, is this the ideal?
There have been numerous studies that suggest that the number one indicator of poverty is a never married woman with children. Other studies have shown that ideally, that a man and a woman raising a child, outside of abuse, is best for healthy emotional development of the child. There are several studies that suggest that rise in violence in the younger generation could be attributed to the hypermasculinity that is more prevalent in families where women are raising male children without the benefit of a positive male role model (husband). We also see problems with girls raised exclusively by unwed mothers, particularly where the mother is still openly dating. With no responsible male role-model for the girl child, she has little idea of what man should act like, other than those she see's in popular culture, or those represented by the men her mom brings home.
This very long posting basically is me getting around to saying that what has gone into the rise of unwed parenthood is that we, as a society, have essentially contributed in the de-emphasizing of of doing what is right, vrs. doing what feels good.
Should I as a male keep my sexual relationships only to those with whom I'm willing to marry? (I'm assuming heterosexual relationships here, since homosexual relationships should not result in procreation without a laboratory.) Absolutely. Cuts out on the amount of sex one could possibly engage in, but.....', OTOH, if you do mess up and impregnate someone you would rather not be with for the next 18 years or so, should you do the right thing and marry the woman if she's willing. Absolutely. It's no longer about you, it's about the kid. And if the woman is not willing, then you still need to be there to help raise the kid, this includes but is not limited to financial responsibities, role model, and child care.
As for women, similar train of thought. Should a woman only "sleep" with someone that they are willing to spend the next 18 yrs. or so with? Absolutely. And as above, if you do mess up, it's no longer about you, it's about the kid. The child didn't mess up, you did.
I firmly believe that when society puts the premium back on having children in wedlock, and of personal responsibilty in preventing unwanted pregnacy prior to impregnation, you will see the incident of out of wedlock children greatly reduced if not completely eliminated.