Linking economic growth pathways and environmental sustainability by understanding development as alternate social-ecological regimes.

Scientists understand how global ecological degradation is occurring but not why it seems to be so difficult to reverse. We used national-level data and a mathematical model to provide an empirical test of the hypothesis that national economies display two distinct economic regimes that are maintained by self-reinforcing feedbacks between natural resources and society. Our results not only support previous findings that two distinct groups exist, but also show that countries move toward one of these two different equilibrium points because of their different patterns of natural resource use and responses to population growth. At the less economically developed equilibrium point maintained by "green-loop" feedbacks, human populations depend more directly on ecosystems for income. At the more economically developed equilibrium point maintained by "red-loop" feedbacks, nonecosystem services (e.g., technology, manufacturing, services) generate the majority of national gross domestic product (GDP), but increasing consumption of natural resources means that environmental impacts are higher and are often exported (via cross-scale feedbacks) to other countries. Feedbacks between income and population growth are pushing countries farther from sustainability. Our analysis shows that economic growth alone cannot lead to environmental sustainability and that current trajectories of resource use cannot be sustained without breaking feedback loops in national and international economies.

Implications of agricultural transitions and urbanization for ecosystem services.

Historically, farmers and hunter-gatherers relied directly on ecosystem services, which they both exploited and enjoyed. Urban populations still rely on ecosystems, but prioritize non-ecosystem services (socioeconomic). Population growth and densification increase the scale and change the nature of both ecosystem- and non-ecosystem-service supply and demand, weakening direct feedbacks between ecosystems and societies and potentially pushing social-ecological systems into traps that can lead to collapse. The interacting and mutually reinforcing processes of technological change, population growth and urbanization contribute to over-exploitation of ecosystems through complex feedbacks that have important implications for sustainable resource use.

How online food delivery platforms contributed to the resilience of the urban food system in China during the COVID-19 pandemic.

We use high-frequency data to quantify the nature and performance of online food delivery platforms during the COVID-19 pandemic in urban China, and to estimate the short- and long-term effects of lockdown and reopening measures. A staggered difference-in-differences (DID) estimation strategy and event study approach are used to identify the effects of lockdown and reopening measures on the performance of online food delivery platforms and restaurants. The results indicate that some restaurants continued to operate and offer online food delivery while lockdowns were in effect. Both the number of operating restaurants and their online food delivery services rebounded and experienced further growth after lockdowns were lifted. The adjustment path of the online food delivery business following the implementation of lockdowns differed from the adjustment path following the lifting of lockdowns. The lockdown and reopening measures did not affect all types of restaurant/cuisine equally. We also examine possible impact mechanisms of lockdown measures on online food delivery and restaurants, and conduct robustness checks to confirm the stability of the main findings. This study contributes to the existing literature by confirming the positive contribution of online food delivery to the resilience of urban food systems in response to unexpected external shocks. Our results have implications for the design of policies to guarantee food supply and help urban food systems adapt to unexpected shocks.

Are only children in China more likely to be obese/overweight than their counterparts with siblings?

Family planning policy in China has resulted in a large number of one-child families. According to Becker's "quantity-quality trade-off" theory there is an inverse relationship between the number of children in a family, and spending per child. We test whether this has led to significant differences in the height, weight and BMI of only-children compared with children with siblings in China using 4414 observations derived from four recent waves (2004, 2006, 2009, and 2011) of the China Health and Nutrition Survey. We use propensity score matching and instrumental variables to control for the possible endogeneity of the number of siblings. Results show that only-children are significantly heavier (1.88 %-3.86 %), and have higher BMI (2.59 %-3.50 %). Moreover, they are more likely to be obese than children with siblings (2.33 %-3.00 %). Further analysis shows that these differences in health outcomes might be attributable to higher consumption of animal-source food (23.90-27.13 g), a higher frequency of eating western fast food (0.48-0.70 times/3-month) and drinking sweetened soft drinks (0.29-0.36 times/month), a higher share of meals eaten away from home (4.67 %-5.31 %), and more sedentary activity (20.04-34.35 minutes/week) by only children. Our study indicates that the growing share of only children due to China's family planning policies also contributes to the increasing prevalence of overweight and obesity in China. This policy has been eased in recent years, which might slow the increase in the prevalence of overweight and obesity and thus reduce the corresponding health burden for Chinese society as a whole.

Restaurants in the Neighborhood, Eating Away from Home and BMI in China.

BACKGROUND: To investigate the association between environmental risk factors, eating away from home, and increasing BMI of Chinese adults. METHODS: Participants were selected from the recent four waves (2004, 2006, 2009, and 2011) of the China Health and Nutrition Survey (CHNS). 10633 participants, including 5084 men and 5549 women, were used in the analysis. 24-h dietary recall data for three consecutive days with information on the time and place of consumption were collected. Nearby restaurants were measured by the number of fast food outlets, indoor restaurants, and food stands in the neighborhood. Random effects multivariable regression was used to assess associations between these variables. RESULTS: People living in neighborhoods with large numbers of indoor restaurants are more likely to eat away from home (p<0.05). Higher frequency of eating away from home is positively associated with BMI, but this effect is only significant for men (p<0.05). Moreover, while eating dinner or breakfast away from home contributes to BMI increase for men (p<0.05), no such association is found for lunch. CONCLUSION: Eating dinner and breakfast away from home is positively associated with BMI for Chinese men. Labeling energy and portion size for the dishes served in indoor restaurants is recommended in China.