What could cause a baby boom across the Western world:
As other posters have mentioned, change economic conditions to make raising a family affordable.
Eliminate inheritance taxes and estate taxes, allowing families to accumulate wealth and retain property over generations. Drastically lower or eliminate property taxes.
Develop a robust varied economy with sectors for all skill levels. Implement economic policies to encourage skilled labor jobs, blue collar and white collar. Lower taxes on businesses, enabling them to hire more workers. Implement balanced tariffs on foreign goods to prevent product dumping and destruction of industries. Drastically limit immigration so the value of labor will increase and the cost of housing will decrease. The goal of these reforms is to make it possible for a family with multiple children to prosper with one working parent, as in decades past.
Raise educational standards and have schools focus on nothing but academics instead of indoctrination. Have different quality level of schools, so motivated children can go to schools where the students are serious about what they're doing. Develop trade education programs for students who want to enter a career field which doesn't require university education. Remove disruptive, violent and delinquent individuals from schools so kids who want to study can be safe.
Promote personal responsibility in schools, since school is like a kid's job.
Eliminate anti-family media bias. Respect women's choices even if that choice is to get married and have children.
Eliminate media promotion of promiscuity, which damages marriage satisfaction.
Reform public assistance law to incentivize marriage.
enter link description here
Reform family court to decrease the devastating financial consequences of divorce, thereby encouraging marriage. Eliminate no fault divorce and grant custody of the children to the parent best able to care for them, rather than court systems habitually awarding custody to the mother. Require paternity to be proven with a DNA test before granting child support. Honor pre-nuptial agreements. Require the same standards of evidence in family court as in civil and court.
Reform domestic violence law and apply enforcement of the law equally to both men and women. Enforce perjury laws against individuals who make false statements to law enforcement.
Promote general values based character education with a focus on consideration for others, personal responsibility, and honesty.