Here's Balkan Insight talking about it, specifically, titled
Helping Hungarians Have All the Babies They Want. Lyman Stone of IFS also did an article on the subject, which explains Orban's policies:
Starting around 2012, but really taking off in 2015 and 2016, women in Hungary started becoming more likely to get married. The marriage rates shown below reflect what share of unmarried women in a given age group the year prior got married in the last year. In most countries, this number is flat or falling, especially for younger women, as the average age of first marriage is pushed later and later. But in Hungary, the rise in the age of first marriage, which has been so inexorable in other countries, has actually stalled out and perhaps started to fall. The country is not just experiencing a fertility spike; Hungary is winding back the clock on much of the fertility and family-structure transition that demographers have long considered inevitable.
This is true even on some unfortunate metrics: unmarried teen pregnancies have risen in Hungary in recent years, even as they have fallen in other countries. Marriage rates of teen women are rising as well, which may be good, or may reflect women being relegated to homemaker roles and kept out of the public sphere, perhaps against their desires.
It’s hard to say exactly what may have driven this turnaround in marriage behaviors. Hungary was hard-hit by the Great Recession, and its GDP per capita took longer to recover to pre-recession levels than many other countries, so it probably is not due to an economic boom.
However, in 2011, Hungary adopted a new, and extremely controversial, constitution. Criticized by many international organizations as consolidating too much power around the ruling party, the document was Hungary’s first democratically produced framework for governing. It includes statements such as, “We trust in a jointly-shaped future and the commitment of younger generations. We believe that our children and grandchildren will make Hungary great again,” and, “We hold that the family and the nation constitute the principal framework for our coexistence,” and “We bear responsibility for our descendants.” It also includes strong language committing the country to historic national heritage, Christian identity, and community values. Moreover, Article L of the constitution, which, again, is the basis of Hungarian government today, says,
Hungary shall protect the institution of marriage as the union of a man and a woman… and the family as the basis of the nation’s survival. Hungary shall encourage the commitment to have children. The protection of families shall be regulated by a cardinal Act.
These changes were largely a surprise to many Hungarians, who are not, according to public surveys, an extremely religious or family-oriented people; in fact, Hungary has the third highest religiously unaffiliated population share in central and eastern Europe. But while it may have been a surprise, once implemented, constitutions can be hard to undo. Whatever exact policy details may be, Hungarians have a durable commitment from their government to make sure that some kind of family support will always exist: it’s written in the constitution! Given the long-term nature of child-rearing, this guarantee may be very important and serve as a positive shock to the long-run family expectations of Hungarian women.
It’s also possible that the proclamation of a constitution so directly aimed at ginning up national feeling, a sense of connectedness to heritage, and a promotion of the family has its own cultural effect. I’ve shown before that “cultural policies” can have large effects on childbearing and marriage: it’s possible that Hungary’s constitutional change is a kind of cultural signal to Hungarians, urging them to adopt somewhat different values.