Qian's research uses rigorous empirical analysis to address big-picture questions in development economics, political economy, and economic history. A common theme in her research is to use institutional details, policy shocks, large demographic and historical data to understand the detailed processes of long-run economic, cultural and institutional development. Her research has been influenced by the works of Amartya Sen. In her most well-known paper - Missing Women and the Price of Tea in China - Qian uses the impact of China's economic opening to estimate the effects of parents' relative contributions to a household's income on the difference between boys' and girls' survival rates, which stands at the core of the phenomenon of "missing women" in China. In particular, she finds that China's post-1978 economic opening caused the price for tea in China to increase as a consequence of greatly increased external demand, which in turn tended to increase the income of women in tea-producing regions; this, in turn, had a substantial positive impact on survival rates for girls and educational attainment for all children.[3]
She (together with Xin Meng and Pierre Yared) also documents that the centrally planned grain procurement policy contributed to around half of the mortality during China's Great Famine.[4] One of her works, falling under development economics, focuses on the how family size affects a child's educational attainment, a relevant question in the field of labor economics. Her extensive research in China led her to conclude that an increase in family size has a negative effect on child educational attainment, an issue that is specifically prevalent in developing countries.[5] In another study, she and her co-authors show that anti-ethnic Ukrainian bias was a major contributor to high famine mortality during the Great Soviet Famine of 1932-33.
Another influential study shows that U.S. food aid is largely driven by U.S. objectives and can lead to more conflict in recipient countries.[6] A well-cited finding using historical data (together with Nathan Nunn) is that the introduction of the potato within the Columbian exchange may have been responsible for at least a quarter of the population and urbanisation growth observed in the Old World between 1700 and 1900.[7] A paper with Nathan Nunn and Sandra Sequeira shows that historical immigration to the United States increased productivity and innovation.[8] Another paper shows that workers in low-income countries accumulate fewer skills on the job than workers in rich countries and this contributes to cross-country income differences.[9]
