1. I've spent an hour trying to find this survey but cannot. My hunch is it's an online survey with questionable reproducibility (especially after looking at similar research produced by Clever)
2. I'm not too surprised by my college aged peers overestimataing average starting salaries. With the increase in CS/ECE students and a relatively small but vocal minority talking about 200K TC out of college, the rest of us assume assume this is a common entry level salary, when in reality compensation is well below that (on a separate note - I HATE the TC designation. that 200k TC is more like 140k/year when you factor in vesting). Heck, the CS program I went to is one of the best programs in the world and even they vocalized that their AVERAGE starting salary was in the 80-90k range, yet most of my peers never realized this.