Btw, you got a computer right? There are thousands of articles and stories that will explain to ya just how significantly illegals have eff'd over wages in venues like S. CA.
Look it up.
What would be useful to me is for someone directly involved on the business side of CA trades with respect to inputting personal experiences. Are these numbers accurate or not?
I have personally experienced illegals in the trades largely working at lower rungs of the wage pyramid with the paying customers largely lower income themselves. At the highest level of the trades, the employers are less likely to be complicit with employing illegals because of liabilities. As an extreme example, several decades ago, there was an explosion at a Texas petrochemical plant during the yearly maintenance shutdown. 47 people were killed, mostly the contract maintenance workers. The root cause is non-english speaking workers and their supervisors had no clue from their safety orientation what lock-out tag-out was nor with the daily task specific instructions were. So, the idiots cut off a padlock from a valve then opened the valve thus flooding a tank with combustible gas that promptly blew up. The petrochemical and refining companies forced reform on the regional safety council to play it straight regarding basic and advanced certifications and this radically weeded out lots of illegals by itself from this higher level within the wage pyramid. Still though, illegals get into the plants largely through maintenance contractors, mainly via larger crews working shutdowns.