We are seeing large drops relative to inflation.

This report outlines how STEM wages have stagnated since about 2000[0]

2015[1] CS graduates have starting salaries that are about 4% lower than 2014[2] graduates. Do that for a few years and it adds up.

Anecdotally, I am a "Senior" software engineer that has been writing software for nearly 20 years (professionally 10), work for a household name software company on the east coast, and having trouble affording any real estate in the area without an insane commute.

[0] http://www.epi.org/publication/pm195-stem-labor-shortages-mi...

[1] https://www.naceweb.org/uploadedFiles/Content/static-assets/...

[2] https://www.naceweb.org/uploadedFiles/Content/static-assets/...

Why would the big companies of SV conspire to fix wages if they didn't want to decrease the cost of labor?

Yes, tech workers are very underpaid, even if their pay is good relative to the rest of the economy right now.

I'm not sure that's connected - if wage fixing were to blame we wouldn't be seeing salary drops, they wouldn't have risen in the first place.

My question is more that I would be very interested to see data supporting the idea that there has been a large drop in developer salaries.