Germany has dropped below Japan to have not just the lowest birth rate across Europe but also globally, according to the report by Germany-based analysts.
Its authors warned of the effects of a shrinking working-age population.
They said women's participation in the workforce would be key to the country's economic future.
Germany's falling birth rate means the percentage of people of working age in the country - between 20 and 65 - would drop from 61% to 54% by 2030, Henning Voepel, director of the HWWI, said in a statement (in German).
Arno Probst, a BDO board member, said employers in Germany faced higher wage costs as a result.
"Without strong labour markets, Germany cannot maintain its economic edge in the long run," he added.
Experts disagree over the reasons for Germany's low birth rate, as well as the ways to tackle the situation.
Mr Probst said the country would need young immigrant workers to fill the significant skills gap. And more women were needed in the workforce to avoid economic problems.
Germany has one of the highest migration rates in the world, but has also seen growing support for anti-immigration party Alternative fur Deutschland (AfD).
The latest birth rate figures comes despite efforts by Mrs Merkel's government to invest in childcare support.
I may be one of them unwashed, ignert 'Muricans and perhaps I just don't get the enlightened, progressive mindset of the Continent but it seems to me that if not enough children is the problem, having more children might just fix it.
Snarkiness aside, this is a major economic crisis that is brewing in Europe and to a lesser but still very real extent in America. It is not a viable economic and fiscal strategy to fail to have workers to replace those who are retiring, especially when those who are retiring have been made expensive promises by the government with a shrinking pool of revenue to fund said promises. At least in America a lot of the workers who are retiring are leaving more highly skilled and paid jobs and are being replaced, if at all, by lower skill workers, often immigrants, who make a commensurately lower wage. In large segments of our population child-bearing is put off until the last moment and often too late. As workers choose to not work and leave the workforce, a number that is growing and not captured in the much touted "unemployment" statistics and other workers self-select through poor performance and lack of motivation to be restricted to "dead-end" jobs coupled with a refusal to have children by married couples, we see that the number and relative strength of the worker pool is getting weaker precisely as the need for tax revenue is greater.
The solutions proposed in this article and similarly here in America make little sense. Encourage more women to enter the workforce? That is supposed to increase child-bearing? Or provide more institutionalized daycare so women can have a baby and then dump it off with strangers so they can go to work to pay for that daycare are supposed to find that experience so wonderful that they want to have more kids? Come on. This obsession with women having "careers" to make a political point is the greatest disincentive to having children so having more of that is not going to magically make women want to bear children for day care workers and the state to raise while they slave away to pay for it.
A society that decides to commit suicide by refusing to replenish itself is doomed to a slow, painful death. Having more women working has done little to help America as a society and now we are following Europe in the slow cultural suicide of childlessness. Maybe it is time for us to stop listening to the social engineering experts and let couples make their own choices about how many children to have and how (and who) to raise them.