Because

It modifies the entire preceding clause. It's an adjunct (adverbial) of reason.

BillJ

OK.

If the sentence were these instead, would you interpret them as the same:

There are more than 150000 men living without their families because of changes of their workplaces.
There are more than 150000 men living without their families because of changes of workplaces.

And a related question. The dictionaries I have say 'workplace' is countable.

I would analyze this in a more traditional and conventional way. The "verb" living is modified by the adverbial phrase, "without their families", and also by the adverbial phrase "because of a change of workplace."

These two sentences I would analyze in the same traditional way. The "verb" living is modified by the adverbial phrases "without their families" and "because of changes of their workplaces/changes of workplaces."

The word "workplace" may, in theory, be countable, but in practice it is not used in the plural.

Your three sentences are grammatical but rather hard to understand beca

TakaWhy do you think the workplace in the sentence is the bare form?

Because there is only one workplace. They were all moved to the same new workplace.

CJ

CalifJim TakaWhy do you think the workplace in the sentence is the bare form?Because there is only one workplace. They were all moved to the same new workplace.CJ

150000 people to the same new workplace? Are you sure?

The text from which I excerpt the sentence in question is about Japanese people today.

And what do you think about the modific

Taka150000 people to the same new workplace? Are you sure?

No, now that you mention it, but it was my first thought.
Each person was moved to some new workplace is more likely if this is about Japanese people today, i.e., because of a change of workplace (for each).

TakaAnd what do you think about the modification? What do yo

CalifJim .Each person was moved to some new workplace is more likely if this is about Japanese people today, i.e., because of a change of workplace (for each)

Then shouldn't it be 'a workplace for each'?

You wouldn't say, for example, 'They went into room' or 'They have book', would you?

TakaThen shouldn't it be 'a workplace for each'?

No. Surprisingly, maybe, but no. 'workplace' is being used almost as a generic noun modifier of 'change', as if it were a workplace change. Apparently change (and probably quite a few other abstract nouns) can be used with an of-phrase without an article and followed by a singular noun, e

So 'a change of room' or 'a change of book' would also sound fine?