In a lot of places in LA, you actually do need to push the crosswalk button in order to get the walk signal when it's your turn--mainly if you're on a major road and you need to cross to the other side of it rather than crossing side streets while staying on one side of the major road (side note: yes, there are neighborhoods in Los Angeles where you can actually walk to places). If you don't hit the button, it won't give you a walk signal when the parallel light is green. Of course, hitting that button doesn't mean you won't be standing around for several minutes waiting for your signal, but it's not a complete placebo.The "close door" button in my apartment building's elevator, however, is worse than a placebo. I swear it actually keeps the door open for longer.
I agree. I'm sure a lot of the walk/don't walk buttons don't have much effect, but I have absolutely seen places where you don't get a walk signal at all without it (and the road is trafficked enough that trying to go with the flow carries a high risk of pancake) so, I end up pushing them in case. That old intermittent reward stuff. However, people who push already lit elevator buttons make me nuts.