It's a dreadful financial choice for a few reasons. If you look at the 'parent' cohort relative to the 'non-parent' cohort:
Disruption to their Education
Juggling study with parenting is difficult, no matter what the circumstance, but for teenagers who fall pregnant while still at school, even basic level education can be difficult to maintain. Studying parents suffer disruption to their education during pregnancy and in the months following their child’s birth. While some continue their education through correspondence or other forms of distance learning, many simply drop out all together.
Reduced Earning Potential
When young parents eventually enter the workforce, their earning potential can be hindered by their disrupted education, and their apparent lack of work experience compared to other people the same age. This sets up a cycle of poverty or financial dependence.
Lack of Financial Security
Becoming a parent while you are still very young means you haven’t had the chance to build any financial security or back-up for when the going gets tough. Whether the parent is on a benefit, or manages to find employment, they simply live week to week with little chance of getting ahead, and a very real risk of falling behind.
Lack of Support from their Partner
Parents of all ages face the risk of an unsupportive partner, but for young parents the risk is even higher. Even if both the mother and father do take responsibility for the pregnancy, most of these relationships eventually end in separation.
The statistics on the average age of a single parent are misleading because they take into account parents of very young kids and teens. There will be many single parents in that group who have been through multiple relationships. Better to have a statistic that shows whether mum is still with the biological dad when the child is three years old, or four years old or whatever. I'm googlign for that now. Hopefully I can find one. I bet the results are markedly different for mums who are in their thirties when they have their first child versus mums who are in their teens when they have their first child.
HOWEVER, even though I don't think it's wise to have a baby young, it doesn't mean it has to be a disaster. There are many many many wonderful young parents out there. And it takes a strong and wise community to realise that children are a gift, no matter how old the parent may be. It takes a village to raise a child.