Basically the low interest rates by Fed and other central banks have led to huge increases in real estate prices which have led to less people being able to afford to buy adequate real estate for their family so families are having 1-2 kids instead of 3-4 kids and many families are never formed in the first place because people are priced out of the real estate market compared to their wages (even with the low interest rates) so not even 1-2 kid families are forming at the needed replacement level.
Only single moms on welfare can make kids since the government pays for their real estate needs.
Then to "fix" this problem caused by low interest rates causing high real estate prices Government in USA has allowed immigration of tens of millions of illegals and tens of millions of mostly low wage legal immigrants which has further worsened the problem by depressing wages for 50% of people and by further increasing the demand for real estate leading to ever higher real estate prices.
EU has done the same with massive immigration from Eastern European countries to EU countries with welfare and higher wages to depress the wages in those countries and Germany has even worsened the situation by importing millions of Turks and France has imported millions of Algerians and other Africans.
On top of this EU has created common asylum rules through EU directives and EASO (European Asylum Support Office) modules and training specifying how asylum claims need to be processed and this led to ever increasing levels of asylum seekers into EU worsened first by leftist Renzi's policy in Italy since 2013 of picking up migrants from near Libyan coast and by Leftist/Communist Tsipras policy of stopping detention of asylum seekers, stopping registration of asylum seekers and stopping border controls in Spring of 2015 which led to huge rush of arrivals through Greece to EU welfare countries.
Then Germany and Sweden LURED Syrians who were all completely safe in Turkey to come to Germany and Sweden with 100% acceptance rates as a political decision for their asylum claims and the free apartment and generous welfare money both Sweden and Germany give out.
When the rush got bad EU solution was to GUARANTEE that Syrians would get through Greece and Eritreans through Italy by starting an EU burden sharing systems for Syrian and Eritrean asylum seekers from Greece and Italy to around EU with most ending up in welfare paying EU countries and this was started in 27th of May 2015 for 40,000 relocations and when the rush of migrants got worse another burden sharing of 120,000 migrants was pushed through in EU by Juncker (Druncker) and Merkel against opposition from Eastern Europe.
Of course this EU Guarantee that migrants would get through Greece and Italy only made matters worse and attracted more migrants and Merkel made matters even worse by declaring "there is NO LIMIT on how many asylum seekers Germany takes" and demanding that borders MUST be kept open.
When Hungary tried to stop the flood and tried to stop migrants going through Hungary and keeping them in NO WELFARE Hungary the migrants got upset and staged riots in Hungary since they wanted German welfare Merkel called Orban every name in the book and Orban responded to Merkel's INSANITY by putting double fences with barbed wire on top to Hungary's borders with Serbia and Slovenia and letting all migrants then in Hungary (in CLOSED refugee camps and CLOSED residences as allowed by EU directives) to go to Germany since Merkel said people should be allowed to go freely because there was "too many people coming to stop them" according to Merkel and Merkel even said Dublin agreement (first EU country registers migrants and processes their asylum claim and there is no forward movement) was NO longer valid.
In the end Sweden got about 200,000 migrants in one year and Germany got about 1 million migrants in one year and many other EU countries with welfare and free apartments got tens of thousands and an epidemic of rapes and gang-rapes and many other violent crimes including terrorist attacks followed.
In Sweden 98% of gang-rapes are committed by migrants or people with migrant background (as reported by Swedish media Expressen) and of all rapes migrants or people of migrant background committed 58% (every Swedish media and BBC) during the last 5 years.
In Germany New Years celebrations will never be the same and 15-year old Jewish girls are now raped and murdered by Iraqi asylum seekers before fleeing back to Iraq to escape getting convicted.
The amount of rape and gang-rape and murder caused by Merkel is inhumane and every rape and gang-rape and murder and rape of children by asylum seekers in Germany is the POLITICAL CHOICE of Angela Merkel because a) she allowed a million to come to Germany even though they came through several safe EU countries and everybody was already SAFE in Turkey so there was NO reason to come at all even for Syrians other than the desire to get generous welfare and free apartment that Germany provides.
Everyone was also SAFE in Greece but they did not want to stay because Greece has NO welfare. If the borders had been closed in early 2015 NOBODY would have come because they do NOT want Greece (99% went through Greece without registration and and out of 1 million only 11,000 applied for asylum in Greece in 2015. b)because EU directives allow every asylum seeker to be kept in a CLOSED refugee camp or CLOSED residence while their claim is processed but Merkel through it would be a good idea to allow the migrants to live in OPEN asylum seeker centers so they could go to German streets at night and to party German New Years eve.
Merkel and Juncker MADNESS continued until late 2015 when Norway, Sweden and Denmark were forced to start border controls to stop the flood of migrants and then in early 2016 Austria and Slovenia closed their borders by allowing only a very limited number of migrants through which caused Croatia, Serbia and Macedonia to close their borders completely (with Czech and Poland sending troops on Macedonia border to help Macedonia keep the border closed) and closing borders CRASHED the number of arrivals to Greece by over 90% so of course Merkel rushed to "solve" the issue Merkel's insistence of OPEN borders had caused by making a deal with Turkey so Turkey would patrol their coast a bit and take back a few hundred Syrians in exchange for EU countries taking 20,000 Syrians from Turkey and on top of that Merkel promised the about 70 millions Turks visa-freedom to Europe.
Merkel is the most incompetent and stupid political leader in European history and in 2015 when she said that there is "NO limit how many asylum seekers Germany takes" and demanded that borders must be kept open and called crazed leftists waving "refugees welcome" placards good people and all people criticizing Merkel's political choices bad people, German parliament Bundestag should have removed Merkel and placed her under observation in an insane asylum.
If EU breaks up it will be because of Merkel's irresponsibility, madness and egotistical moral posing.
German press and media takes part of the blame because they HID even the massive sexual harassments and sexual assaults on New Years eve 2015-2016 for 6 DAYS before they were forced to report it because thousands of Germans were reporting it on Facebook.
Later Germany made a law cheered by Merkel that Facebook and other Social media has to remove "hate speech" as determined and reported by German authorities in under 24 hours or incur massive fines.
If this Soviet Union style law was in place in New Years eve 2015-2016 then Merkel's minions in German government would have demanded removal of all the "hate speech" of thousands of Germans reporting massive sexual harassments and sexual assaults by asylum seekers and other migrants in New Years eve 2015-2016 and Merkel could have escaped the blame for Merkel's POLITICAL CHOICES and Germany would be living in a Soviet Union style fakeness where one could NOT criticize Communism but Communism would be just replaced by migrants, asylum seekers and Merkel's totally INCOMPETENT political choices.