Zhao Yaohui has been working out of her office at Peking University's National School of Development for almost a decade, and it shows. Bookshelves on facing walls are packed to the brim, mostly with economic tomes, random items are piled on the floor, and a hair dryer hides under her computer table.
She offers me a drink and a seat - on her sofa bed. "The office is messy," says the softly spoken Zhao. "I got the hair dryer yesterday because I rushed out and didn't have time to dry my hair."
Work seems to be her life, but it soon becomes clear that the reverse is actually true: Zhao's life has a profound influence on her work. An economics professor, Zhao is a principal investigator of the China Health and Retirement Longitudinal Study (CHARLS). A massive biennial survey, it will provide the bedrock of data for Chinese policymakers who must find ways to care for the rapidly ageing nation.
More than 17,000 participants, aged 45 and older, are interviewed on a broad range of topics from socioeconomics to physical and psychological health. Figures from the baseline study, released last week, show that a third of China's elderly (people aged 60 and above) report poor health, and a quarter are struggling below the poverty line.
Rural residents, who make up about 70 per cent of the population, tend to be worse off in health and wealth. Using consumption as a measure of standard of living, the poverty rate among rural elderly is 29 per cent compared to 10 per cent of urban elderly. Fifty-seven per cent of rural elderly receive no pension, compared to 16 per cent of their urban counterparts.
In many ways, Zhao, 49, says she identifies with the study's findings. Born in Beijing, Zhao and her family moved to Xuzhou in Jiangsu province when she was little. She returned to the capital to attend Peking University, completing her masters in economics there. She headed to the University of Chicago on a scholarship, obtained her PhD in economics, and later taught at George Washington University.
Zhao has taught at Peking University since 1996 and is comfortably off, but she too struggles to care for her elderly parents. Her father, aged 80 and suffering from Parkinson's, and mother, 78, now live in Shijiazhuang, the capital of Hebei province, about 280 kilometres southwest of Beijing.
Zhao, a middle child, is solely responsible for taking care of them because her elder brother and younger sister work overseas. "My parents are miserable," she admits, saying they are in poor health and miss their children. "I want them to move to Beijing to stay with me, but they don't want to."
Many of her relatives have rural hukou, or household registration. The hukou, which officially identifies a person as the resident of an urban or rural area, is important because it determines access to a range of social and economic benefits, from housing and education to health care.
In fact, the main reason Zhao's parents have been reluctant to relocate is health insurance. "My father's health insurance is not portable, so their health costs will not be covered in Beijing except in an emergency," she says.
It's an issue highlighted in Zhao's study. Coverage rates among China's elderly have improved owing to the government's expansion of health care insurance programmes since the mid-2000s: they are 92 per cent and 94 per cent in the urban and rural areas respectively.
But the financial burden of medical costs can still be very high, benefits are disparate across programmes and the schemes have poor transferability.
"I think it's important to identify the barriers to migration. The system should make it easier for people to migrate," says Zhao.
Much of her research, therefore, has focused on labour migration, which the government restricted for decades. This has resulted in a large urban-rural income and health gap. Even after three decades of reform on the mainland, urban residents still enjoy preferential treatment for pensions, insurance and housing.
"I have many rural relatives," says Zhao. "They are really, really poor. I'm concerned for their well-being. People need to leave agriculture to earn a higher salary and have a better living."
There are other barriers to migration: a higher cost of living, cramped housing, and most of all, social connections. "One thing they do have in the countryside is big houses and lots of friends," she says.
So her parents are staying put, for now. Fortunately, supporting them financially is not a problem. But many of her friends have no siblings, being products of the one-child policy, and are having a hard time caring for their parents.
Deep-rooted Confucian notions of filial piety have helped sustain an informal form of old-age security, but traditional family values are changing, as households become smaller and society becomes more mobile.
At present, people aged 65 and older have between three and four children on average, while those aged 45 to 49 have fewer than two. In 10 to 15 years, people reaching old age will likely have fewer children due to the one-child policy.
Zhao has two sons - one is fresh out of Princeton University, the other is six. She admits to being anxious about being cared for in her old age. "It looks like sons are less reliable than daughters. From my observations, daughters are more caring."
But didn't her study find that sons were more likely to live with their parents? "They may be living together, but the quality of relationship may not be as good," she explains. "In another study, we found that because parents treat their sons better from a young age, sons feel a responsibility to take care of their parents, whereas daughters feel a necessity to do. Some other studies have found that parents are happier if they live with their daughters."
The other worry is that her sons' generation may experience a "wealth hump", because, unlike her generation, they would have missed the chance to capitalise on the property boom.
Indirectly, Zhao's study could help assuage some of her fears. The survey data measures the existence and impact of social safety nets, and gives policymakers and researchers critical insights into the world's most rapidly ageing population. This will hopefully influence future policies, which will ultimately affect Zhao and her family.
More immediately, the survey has had an impact on her students, who volunteer to conduct the fieldwork. "Many of my students are from Beijing or Shanghai, and have never been to the countryside. The study has really opened their eyes to the realities of China," says Zhao.
"As future leaders of the nation, they should understand how ordinary Chinese live, put themselves in those shoes, and see how they can help."
US institute behind study on elderly
It may come as a surprise that a massive, unprecedented study on China's elderly was initiated by American researchers and is funded primarily by the US National Institute on Ageing (NIA).
But not for Dr James Smith, the economist who in 2005 proposed the China Health and Retirement Longitudinal Study. "I would have been shocked if it was done the other way," says Smith, who holds the chair in labour markets and demographic studies at the Rand Corporation.
"Traditionally, if China did this kind of survey they wouldn't let the data out. If it was funded by the Chinese government, there would be sensitivity to the ageing issue."
Smith was part of a group of researchers who developed the NIA-funded US Health and Retirement Study in 1992, a biennial study that has served as the model for 30 other similar studies worldwide.
To kick off a study in China, Smith approached his former Rand colleague, Dr John Strauss, a University of Southern California economics professor who has been working with Peking University since 2004.
Strauss roped in Peking University colleagues Zhao Yaohui and Justin Lin Yifu (who in 2008 went on to be the World Bank's chief economist). Both knew Smith, a fellow University of Chicago alumnus. The rest is history.
Dr Richard Suzman, director of the NIA's Division of Behavioural and Social Research, says this is "a golden age" for international studies on ageing.
"We've never had as much comparable international data as now. This has brought new researchers from different fields into ageing," says Suzman. "I think we're all the better for it, because we really need all the brain power, data, and resources we can get. We have to learn from each other."
NIA also funds about half of England's ageing study and about 10 per cent of the central costs of that in Europe.
"As different countries adopt different policies, we have in effect a series of large-scale experiments," says Suzman.
"My hope is that cross-national research that allows us to learn from each other's planned and unplanned experiments will accelerate the expansion of healthy life expectancy."