Inspiration for Bill Emmott’s latest take on Japan came from his wife. Observing he had “never really talked to Japanese women” she suggested he make them the subject of his next book. A fine idea, he concurs.

This does not seem a compelling reason to add to the canon of material on what is a perennial topic. Japan, a country of scant natural resources, rose from the ashes of war on the back of mainly male human capital. But now, with a shrinking and ageing population, it must confront the once unthinkable: supplementing the labour force with more women, immigrants or (most likely) both.

Policymakers and economists, both at home and abroad, have highlighted the dividends this could bring. Kathy Matsui, an economist at Goldman Sachs who has long championed “womenomics”, reckons unleashing female work power could boost annual economic output by 10-15 per cent.

Emmott rehearses the arguments and provides a multi-point plan to right the balance. A former editor of The Economist whose earlier book on Japan, The Sun Also Sets, won him both fans and critics, he presents his argument in a journalistically easy-to-digest package. First comes Japan’s gender failings: fewer women at the top universities and in science; a shortage of childcare places. This is followed by interviews with 20-odd women in fields such as politics, the arts and business. And then he presents his policy prescriptions.

The key problem, which he alludes to, is that the picture is not as straightforward as popular wisdom has it. Indeed, female participation in Japan’s workforce is higher than in the US. But — again, not unlike the US — many of these are in low-level temporary jobs: half of the 2.5m increase in female workers since 2013 go to “non regular” jobs. In other words: less security, less pay and less training.

A separate issue muddying the waters is that changes already under way have yet to feed through. Far more women attend university now than in the 1970s and 1980s — roughly the sort of period most Oxford colleges went co-ed too. As the graduates of the 2000s work their way up, more women will be in line for senior positions.

Still, few would disagree that Japan lags sorely on this score among rich countries. Emmott cites failure to approve the contraceptive pill, which helped define the free-loving 1960s in the west, until 1999. He also points to scandal at one of the top medical universities that gave places to low-scoring men over women who received higher grades and an outcry over the compulsory wearing of heels at work.

All this is rich fodder, which makes the second section disappointingly flat. Emmott seems at a bit of a loss among his band of female politicians, entrepreneurs and artists. The long white-varnished nails of one business boss, he imagines, are used as symbols to emphasise her clean recycling business. (Memo: sometimes nail colour is just nail colour.) Another plays the piano for her male colleagues after board meetings. “But this,” reckons Emmott, “may well make them feel subservient to her . . . rather than the other way round.”

None seem terribly interested in profits (arguably a Japanese problem rather than a female one). One executive takes inspiration from a one-time chairman of Japan Airlines who said — and she quotes — “he took on the job not to restructure the company but rather to make the employees happy again”.

Another, working for ecommerce group Rakuten, takes pride in increasing the proportion of accepted refund requests from 20 per cent to 90 per cent. This was achieved by refunding first and investigating later, which seems more open to abuse.

Few have any startling insights; when interest flares up it is quickly snuffled out. Terada Chiyon, now in her 70s, ran the family home removal business with her husband as underling. It worked, she says, because “we had a common dream to make the company bigger”. Unfortunately it turned out he harboured another dream: luring teenage girls into bed. Mrs Terada eschewed divorce and drama. “We cannot deny that our reputation was diminished and our business was affected because such a case happened,” she tells Emmott.

Japan’s Far More Female Future is a useful parsing of the issue; and concludes with a solid prescription for change. Yet whether it will actually sway the debate is doubtful, not least given the groupthink intransigence at the top in Japan.

‘Japan’s Far More Female Future: Increasing Gender Equality and Reducing Workplace Insecurity Will Make Japan Stronger’, by Bill Emmott, Oxford University Press, £30, 224 pages