Researchers Rachel Margolis and Mikko Myrskylä followed 2,016 Germans who were childless at the time the study began until at least two years after the birth of their first child. Respondents were asked to rate their happiness from 0 (completely dissatisfied) to 10 (completely satisfied) in response to the question, "How satisfied are you with your life, all things considered?"
"Although this measure does not capture respondents' overall experience of having a child, it is preferable to direct questions about childbearing because it is considered taboo for new parents to say negative things about a new child," they wrote.
The study's goal was to try to gain insights into a longstanding contradiction in fertility in many developed countries between how many children people say they want and how many they actually have. In Germany, most couples say in surveys that they want two children. Yet the birthrate in the country has remained stubbornly low — 1.5 children per woman — for 40 years.
Margolis, a sociology researcher at the University of Western Ontario, and Myrskylä, director of the Max Planck Institute for Demographic Research, found that most couples in their study started out pretty happy when they set out to have their first child. In the year prior to the birth, their life satisfaction ticked up even more, perhaps due to the pregnancy and anticipation of the baby.
It was only after birth that the parents' experiences diverged.
About 30 percent remained at about the same state of happiness or better once they had the baby, according to self-reported measures of well-being. The rest said their happiness decreased during the first and second year after the birth.
Of those new mothers and fathers whose happiness went down, 37 percent (742) reported a one-unit drop, 19 percent (383) a two-unit drop and 17 percent (341) a three-unit drop.
On average, new parenthood led to a 1.4 unit drop in happiness. That's considered very severe.
To put things in perspective, previous studies have quantified the impact of other major life events on the same happiness scale in this way: divorce, the equivalent of a 0.6 "happiness unit" drop; unemployment, a one-unit drop; and the death of a partner a one-unit drop.
The consequence of the negative experiences was that many of the parents stopped having children after their first.
The data showed the larger the loss in well-being, the lower the likelihood of a second baby. The effect was especially strong in mothers and fathers who are older than age 30 and with higher education.
Surprisingly, gender was not a factor.
"Fertility is a choice for most people in the developed world … [I]f the transition to parenthood is very difficult or more difficult than expected, then people may choose to remain at parity," the researchers wrote.
Margolis and Myrskyla wrote that challenges of new parents that impacted their decision to have another fell into three categories. The first two had to do with health. Mothers reported physical pain and nausea conflicted with their desire to work. Fathers expressed concern about the medical issues of their partner. Second, complications during the birth also appeared to shape their decision to not "go through it again."
The third category was the most significant and was about "the continuous and intense nature of childrearing." Parents reported exhaustion due to trouble breast-feeding, sleep deprivation, depression, domestic isolation and relationship breakdown.
The findings are likely to be eye-opening for some policymakers who are concerned about low fertility rates in their countries and suggest that governments should consider giving additional support to new parents.
As for after the first year, how a child impact's a parent's happiness is anybody's guess. The German survey is annual so we may know more soon.