The Berlin housing crisis is very much happening almost everywhere. City-wide average rents increased 45% between 2009-2015. Rents doubled in some districts in that timeframe and even in the least affected areas (Marzahn and Spandau) rents increased by more than 30%.

I'd argue that's a reflection on what I said before (prices normalizing from dirt-cheap). I do not consider these numbers a crisis at all.

Here is an example of why the Bay Area is in a crisis: https://abcnews.go.com/US/san-francisco-resident-fights-sudd...

A San Francisco man had his rent increased from $1800 a month to $8000 a month. True, it is one of the more extreme examples, but this is what I would call a crisis. Can you show me examples like this from Berlin?

The situation are a bit different though. The Bay Area is competitive despite its housing market, while Berlin to a large extent is competitive because of its housing market. If rents become similar to other major European cities Berlin will lose a lot of its appeal and potential compared to those other cities.

Silicon Valley became what it is today because there was cheap industrial land for chip fabs and random startups.

Debatable. As far as I know it wasn't really until around 2000 that Silicon Valley became dominate enough to really set it apart from other regional technology centers like Dallas, Boston or Pittsburgh.

In any case that doesn't really help Berlin if it takes, say, five years for its housing market to catch up to its European neighbors.

What? You're overlooking an enormous number of factors.

If it's cheap industrial land alone that made Silicon Valley how did Texas, Nevada, The Midwest and other places miss out on a tech business boom?

Texas has TI which is a big tech firm.

45% in 6 years is 6.21% compound per year, which is not unusually high for that time scale for an attractive large city.

Are the wages rising as fast? I would doubt it.

Probably not but that's again a global problem not a Berlin problem. My point was only that Berlin is not specifically harshly affected by these global trends, it's that way (or worse) in pretty much every attractive major city.

but rent was also dirt cheap in 2000-2010, so its more moving towards the average in other big german cities now.

Even 5 years ago when I spent 3 months in Berlin the idea of calling Neuköln trendy would have seemed pretty nuts. So I think that suggests something radical is happening.

I think your memory may be faulty or you weren't that well integrated into the local "scene". 5 years ago was 2013, I was already living in Berlin back then and Neuköln was already billed as "the next Kreuzberg". 10 years ago...you may have had a point.

But also remember that then and now we're only talking about very specific areas of Neuköln which are super hip, it's actually a huge district and most of it is still "not cool". The bits close to Tempelhofer Feld and Kreuzberg have been gentrifying for many years.

You're spot on. I just checked and I was there in 2009. Feeling old now.

Even in Lichtenberg, certainly not trendy at all, rents have increased significantly (although not doubled yet afaik).