relative clause reduction

[ShirleyLing]

David Cameron: we will offer the radical new direction the country is crying out for - Telegraph

But the crisis we face today is not just about debt – it's about jobs. There are already two and a half million people unemployed. That could rise as high as three million.

"people unemployed" could easily have been "people who are unemployed." There must be some esoteric rule on when you can dump "who be/is/are" or "that be/is/are". Could the native speakers offer their opinions on this?

[5jj]

David Cameron: we will offer the radical new direction the country is crying out for - Telegraph


"people unemployed" could easily have been "people who are unemployed." There must be some esoteric rule on when you can dump "who be/is/are" or "that be/is/are". Could the native speakers offer their opinions on this?

No. There isn't a rule.

The relative pronoun and BE are frequently dropped before present and past participles and some adjectives, but sometimes it just does not seem right.

...it's about jobs. There are three million people unemployed. This is fine.
There are five people unemployed in that room. This appears strange, though it is possible if a manager is complaining about five workers who are just sitting around.
There are five people playing cards/exhausted/hungry in that room. Possible
There are five men white in that room. Not possible if we are referring to fair-skinned people - though just about possible if we are refering to terrified or flour-covered people.

The safest suggestion for learners, until they develop a feel for the constructions, is to use either an adjective+noun or a non-reduced relative clause:

There are x people who are unemployed...
There are x unemployed people..

Please do not start yet another thread on this. We do ask people to start different threads for different questions, but your questions are very closely related. We now have three or four threads going on almost identical points. You are very likely to receive confusing and conflicting answers in different threads.

[ShirleyLing]

I'll just leave well alone on this subject.
Thanks for your time and patience

[ShirleyLing]

I have one final question before I will truly let this subject die.

Using "White", "African American", and "Asian" as singular adjectives, and all are preceded by plural numbers:

"The racial makeup of the town was five White, seven African American, and ten Asian." is grammatical.

But,

"In the room, there were five White, seven African American, and ten Asian."

is not grammatical?

[5jj]

On its own, ""In the room, there were five White, seven African American, and ten Asian" is not acceptable. It needs to be:

"In the room, there were five whites, seven African-Americans, and ten Asians"

or:"In the room, there were five white, seven African-American, and ten Asian people".

[ShirleyLing]

It seems that "The racial makeup of the town was" has some special qualities that "There were" doesn't.

[5jj]

It seems that "The racial makeup of the town was" has some special qualities that "There were" doesn't.

It's not 'special qualities'. They are almost as different as: 'This table shows the percentages of people of differnt ethnic backgrounds...' and "I can see...'.