Women can play a larger role at today’s more mechanized construction sites. In the near future, an increasing number of women raising young children will take up construction work.

Not only can but must. Until I see more women doing dirty and disgusting jobs, I'm going to assume the pay differential is at least partially related.

I dunno. I remember when the USA was doing the same thing, promoting women in construction. It's something that should be done, but in USA, once kids leave the everyone-is-equal nest in K-12 and go into a male-dominated industry they're likely to assume the attributes of the new industry, so it would be expected to be a long, hard slog. Not sure if Japan even has the "everyone-is-equal nest in K-12".

Would be interested to hear of the great leaps in mechanization of construction sites that make this suddenly feasible. What was so different before? Men of the recent past were not picking up 1000-pound-plus transformers using only correct lifting technique, were they?

And like scipantheist said, "dirty and disgusting jobs". Construction trades are not as subject to the M-curve, so if economics was the only thing at play here, you'd think women would jump at the chance for construction jobs. If you are out of white collar work for a year, recruiters might count you as stale and expired, not keeping up with your trade. It is bull, but there it is. Wouldn't expect the same bias on construction, which has a lot of seasonal or by-the-project aspect to it, anyway. (That is to address why women don't choose the construction trade, not why men keep barriers to women up.)

http://www.washingtonpost.com/blogs/she-the-people/wp/2014/06/11/report-women-still-face-barriers-in-construction-trades/

... research indicates that women hold 47 percent of all wage and salary jobs, but only 2.6 percent of all construction industry jobs.

Sounds good on paper, but with the semi-regular reports of random metal sheets or blocks falling and killing people... I cant say I would be comfortable with my wife do this work... Not that I am in charge of what she wants to do...but I would surely voice my concerns, especially with our two infant children.

I say this as an open minded husband regarding her work. (she was a ski instructor, for example)

I find it slightly difficult to believe that construction work for women is going to be the wave of the future. the only thing the average young Japanese women is interested in lifting is department store shopping bags.