Logically, that should apply to both young and old. The fact that it doesn't in practice says something else is in play here. FWIW, I think it's clear that older people are more likely to have a sound work ethic. Hell, I didn't develop one until my early 30's. So why do employers (Richard notwithstanding) discriminate against older engineers?

In my not so humble opinion, I think it's due to one factor. Young kids don't yet know the ropes; they fear for their jobs. No young engineer is going to tell his clueless boss that what he's asking for is an NP complete problem and therefore can't be done in the time constraints demanded. Even if the kid knows that it's mathematically provable, he knows his pointy-haired boss wouldn't understand the math, and he's not going to risk his job by telling him the truth.

So he lies, and comes up with that list of "reasons" why the job isn't done.

Older engineers aren't going to put up with that kind of stupidity. They are more likely to tell the dumb marketing dweeb that he's asking for 10 pounds to fit in a 5 pound bag, and it can't be done. Bosses don't like that!

Case in point: At one company I and other engineer were asked how long it would take to do a certain job. Our honest estimate was 6 months. Needless to say, the PHB found that unacceptable. So the other guy and I put our heads together and determined that if we burned the midnight oil continuously we could do it in 4 months.

The PHB accepted that, but then kept pulling us off the job to put out "forest fires". Little had been done on it until two weeks before the due date, when the PHB held a staff meeting to discuss the problem. Upon asking those involved (me, the other guy, and the VP of engineering) if we could pull it off, there was lots of hemming and hawing until it came to me. I told him straight out that we couldn't finish a 4 month job in 2 weeks.

I have never in my life seen such an unprofessional display as was put on by this clown who fancied himself a CEO. He literally banged his fist on the table and screamed.

I kept my job for a few years longer only because I was indispensable, but eventually I was outta there. I don't think it's a coincidence that the company folded a little over a year later.

The bottom line is that young kids, when faced with management stupidity, will bend over and spread 'em. Older guys will, although politely and logically, explain to the idiot that he is, well, an idiot. That pisses them off.