Demographer M. Giovanna Merli hopes her studies of HIV in China can lead to better health policies. Photo credit: Megan Morr

Durham, NC - China has a unique demographics story, a story of population engineering guided by controversial policies that has helped the world's most populous nation bring its population growth under control. Its population is increasingly aging, and the ratio of men versus women has been turned on its head.

Duke demographer M. Giovanna Merli, a new associate professor of public policy studies and a member of the Global Health Institute faculty, is going behind the numbers to study the social aspects of population change. She wants to know how the population trends are influenced by policies such as limiting families to one child.  

"Because the population of China is a uniquely controlled entity, it raises issues of public policy, politics, individual choices and societal influences," Merli said. "So it really enticed me to understand the mechanisms and dynamics that produce a certain population outcome, such as to get women to have fewer children."

It was not demography that first drew Merli to Chinese studies, but rather an interest in its contemporary history and politics, which were widely discussed in her native country of Italy. She enrolled in a program in oriental languages and literatures at the University of Venice, where she added Chinese to her repertoire of Italian, English, German and French.

She then spent three years in China studying contemporary Chinese history, eventually taking courses in demography. After moving to the United States, Merli earned advanced degrees from Johns Hopkins University and the University of Pennsylvania. She was a faculty member at the University of Wisconsin for nine years before coming to Duke.

Merli's early research explored whether the strict implementation of China's one child policy has actually changed fertility preferences among Chinese women.

She surveyed women in four counties that differed in terms of policy enforcement and socio-economic development. She found that the current generation appears to be more willing to accept fewer children in part because of the "one child message" that it has been subjected to over the last three decades. Merli now plans to question women in the urban area of Shanghai to further tease apart the role that socio-economic influences and population policies play in fertility preferences.

That research is just part of a larger study Merli is conducting in Shanghai to look at another big question -- the dynamics of HIV transmission in China. Despite a prediction made by UNAIDS over five years ago that the epidemic was likely to spread throughout China from high risk groups to the population at large, the prevalence of the disease has remained remarkably low.

The prevalence of HIV/AIDS in China is only one tenth of a percent, compared to 18 percent in South Africa. Merli is interested in explaining why that is and whether the epidemic will ever take root in China.

To start, she is conducting a survey in Shanghai to document patterns of sexual behavior and sexual mixing between population groups. The survey asks participants to name not just the number but also the characteristics of their sexual partners, because those characteristics are what may ultimately determine the potential for the HIV epidemic to spread.

By leading to a better understanding of the population groups that are most relevant to the spread of HIV, this study may identify future policies to target high risk groups and prevent the transmission of HIV to the general population. To Merli, such challenges are the best part of her job.

"There is always a puzzle to solve, a puzzle with huge implications for the well being of the population under study," Merli said." With demography, you have a unique set of tools but you often also need to borrow from other disciplines to solve these puzzles. It is an exciting discipline to be involved in, because you feel like you are always learning something new."