Many thanks to Marek M., who pointed me to this chart based on a report provided by the German government to the Bundestag on 15 December 2016 (pdf, numbers from p. 245).
This is it -- the one chart everyone needs to see before forming an opinion about immigration to Germany. The One Chart to Rule them All.
The brown line is the number of deportations from Germany in a year. The blue line is the number of illegal entries.
Just let that sink in for a minute.
Now, a few brief comments.
First, the notion that the 2015 influx is just a blip which will work itself out in the long run is false. In the mid-1990s, German policymakers suddenly decided that they would no longer try to actually deport all the people who entered Germany illegally. Starting in 2009, they essentially gave up on the idea of deporting any more than a tiny fraction of illegal immigrants. Even before the migrant influx of 2015, Germany as a whole was only managing to deport about 10% of all the people in Germany who had already been denied asylum.
Second, this breakdown in law and order is a result of many thousands of individual choices by actors in every single branch of the German government.
State governments. Organizing and enforcing deportations is the responsibility of individual German states, so the overall total abdication of deportations is a reflection of policy changes in all 16 German states. Some are much more dedicated to enforcing the law than others, but overall, the trend is downward.
Immigration bureaucrats. The individual decision-makers at immigration agencies can invoke dozens of exceptions to permit people who have already been denied asylum to stay in Germany. They can recognize a special exception for family members, or because of medical problems, or find that conditions in the immigrant's homeland are too unstable, or simply decide not to 'enforce' an existing immigration order.
By far the most common technique they apply is Duldung (toleration), in which someone who has no legal right to be in Germany is allowed to continue staying here as a matter of toleration -- basically, the administrator uses his or her discretion to decide that if an illegal immigrant isn't causing a significant problem or has some argument why he should be allowed to stay, he will be permitted to stay in Germany for a temporary period, which can be renewed indefinitely.
Bureaucrats all over the world, like most people, have a noticeable preference for deciding cases in such a way as to create as little work for themselves as possible.
If Bogdan presents you with an obviously fake-looking medical certificate from a notoriously corrupt doctor, you have one of two choices. Either you continue Bogdan's 'tolerated' status, in which case he goes home happy. Or you start a tedious, time-consuming investigation into the genuineness of the certificate. Followed by the tedious, time-consuming, emotionally draining, stressful process of actually getting Bogdan deported. Bogdan has many chances to appeal a deportation order, so the process will take years. During which both Bogdan and his children will set down ever-deeper roots, making uprooting them that much more difficult.
Example: The attempt of police to pick up a rejected Afghan asylum-seeker to deport from a trade school in Nuremburg recently resulted in an all-out riot in which hundreds of the student's classmates blocked a street and threw bottles and even a bicycle(!) at the police, resulting in nine injured police officers:
Who wants all that aggravation?
Notice that this bureaucratic inertia results in perverse outcomes: a well-integrated illegal immigrant who admits he could be deported but argues that he should be allowed to stay simply because he's making a contribution will be at high risk of being deported. An illegal immigrant who lies to authorities and manipulates the system (like the Afghan (g) whose deportation caused the riot) will have a greater chance of being allowed to stay, since disproving his bogus arguments and denying his appeals will take so much effort. The squeaky wheel gets the grease.
The courts. The German government sometimes passes laws designed to modestly adjust immigration laws to make them somewhat more restrictive. But none of these will have much effect if courts are generous in recognizing exceptions. German courts are notoriously all over the map when it comes to handling immigration appeals; some are soft touches, while others are rigorous. But the highest German courts often hand down decisions based on the German constitution or human-rights treaties which blow massive holes in the legal framework designed to enforce deportations.
One example is the 2013 decision by the German Federal Constitutional Court (g) on paternity questions in immigration cases. German law rather unwisely provides that a father's decision to officially acknowledge paternity of a child cannot be questioned. This law immediately set up a loophole in immigration law: pregnant women could fly to Germany and request asylum. They would immediately be granted temporary asylum based on a provision of German asylum law which extends automatic recognition to all pregnant mothers.
While being cared for in Germany (at German taxpayers' expense), the human trafficker running the operation pays € 5,000 (the going rate, according to reports) to a German male, who then files an official recognition of paternity. Since the child is now the child of a German father, the child automatically becomes a German citizen when born. And the mother automatically gets a residency permit, since it would be inhumane to break up the family. The father could theoretically be required to pay child support, but the ones who participate in the racket are all on welfare anyway, so they are exempt from child-support obligations. Immigration authorities went to court to argue that they should be able to conduct official paternity tests to disprove the claim of fatherhood, but the Federal Constitutional Court rejected their appeal in 2013. Allowing the authorities to contest the fatherhood claim, the Court reasoned, would create an unacceptable risk that the child might end up stateless.
The result? There are now 700 suspected cases (g) of this form of immigration fraud in Berlin alone. According to the investigative report, many of the mothers ended up becoming prostitutes, working for the human traffickers who imported them and financed the fake fatherhood certificates. The report linked to just above profiles a particularly ironic case: the German 'fake father' who claimed he had a child with an illegal Vietnamese immigrant was actually a far-right extremist an prominent member of the extreme-right NPD party. Apparently the prospect of a quick € 5,000 was more important to this neo-Nazi welfare case than protecting the racial purity of the German Volk. Are you as shocked as I am?
The system is completely broken. Only the foolishly honest or stupid actually get deported, the cunning and the criminal get to stay. Further, everyone across the world understands this: if you somehow manage to set foot in Germany and have some reasonable understanding of German law, there is about a 90% chance you will be able to remain in Germany for the rest of your life, regardless of all the carefully-wrought provisions of German law.
UPDATE: I updated this post on 7 June to reflect that the chart itself is not actually contained in the report, and that the numbers on which the chart is based appear on p. 245 of the linked document.