Conference Agenda

Session
Air pollution 3
Time:
Wednesday, 18/June/2025:
2:00pm - 3:45pm

Session Chair: Jasper Paul Röder, University of Hamburg (UHH)
Location: Auditorium G


Presentations

From Digital Carts to Cleaner Air: The Role of E-commerce in Reducing Urban Air Pollution

Lan An1, Zhenghong Wang1, Ruoming Lyu2, Zhou Huang1, Cong Peng1, Ke Rong2

1Peking University, China, People's Republic of China; 2Tsinghua University, China, People's Republic of China

Discussant: Albert Duodu (Aalto University)

E-commerce represents a rapidly growing share of consumer spending and generates considerable economic profits in the developing world, yet its environmental impact remains underexplored. While online shopping reduces trips to physical stores and lessens individual vehicle usage, the rising demand for logistics

exacerbates congestion and intensifies strain on urban transport systems.

Using a comprehensive e-commerce and air quality dataset covering 283 Chinese

cities from 2016 to 2021, we investigate the net environmental impact of online

shopping by examining the change in nitrogen dioxide (NO2) concentrations in

response to the increased e-commerce demand surrounding the annual Singles’

Day shopping festival, an influential online retail discount event in China. We

employ Baidu Index search frequency data for keywords ”Tmall” and ”Taobao”

during the two weeks before and after the event as a proxy for city-level online

shopping activities, capturing the sharp increase in consumer demand triggered

by Singles’ Day. We find a sizable reduction of 5.97% in NO for every 10% increase

in online purchases immediately following the event. The effect is significant

but substantially smaller in magnitude (1.87%) in the long term, as city-specific

factors and broader economic activity are considered. To address concerns of

endogeneity, particularly the potential reverse causation that cities experiencing higher levels of air pollution tend to engage in greater e-commerce activity, we

use e-commerce service quality as a valid instrumental variable and include extensive city-level controls. Our result is also robust to additional covariates, different specifications, and alternative measures of online purchasing intensity. Heterogeneity analysis suggests that cities with lower concentrations of online suppliers and higher levels of e-commerce import activity experience greater reductions in NO2 levels.

higher levels of air pollution tend to engage in greater e-commerce activity, we

use e-commerce service quality as a valid instrumental variable and include extensive city-level controls. Our result is also robust to additional covariates, different specifications, and alternative measures of online purchasing intensity. Heterogeneity analysis suggests that cities with lower concentrations of online suppliers and higher levels of e-commerce import activity experience greater reductions in NO2 levels.

Our paper provides the first empirical evidence that online shopping benefits

the alleviation of NO2 concentration, suggesting that shifts in consumer behavior—prompted by the convenience and accessibility of online shopping—can

mitigate some of the negative environmental impacts typically associated with

traditional retail activities. We further investigate the redistribution of NO2 emissions driven by e-commerce, both within and between cities. These findings

contribute to a deeper understanding of e-commerce’s environmental footprint

and offer guidance for policymakers pursuing sustainable urban development in

a digital economy.



Local Import Competition and Firm-level CO2 Emissions

Albert Duodu1, Zouheir El-Sahli2

1Aalto University, Finland; 2International Mometary Fund

Discussant: Lars Hecker (Kiel Institute for the World Economy)

It is established in the literature that import competition may lead to efficiency gains in the firms facing it. However, it is unclear whether such gains extend to the environmental behavior of the firms. We contribute to the literature by investigating how local import competition, defined at different spatial dimensions within Sweden, may affect CO2 emission intensity by the local producing firms. Using detailed geographical information about the location of all manufacturing firms in Sweden, we find evidence that local import competition reduces firm-level emissions. This is in contrast to import competition nationwide. This effect wanes with the distance between the producer and the importer. The emissions reduction is driven by productivity spillovers, changes in the product mix, and emissions abatement investment.



Unveiling the Green Trail: FDI, Global Value Chains, and Firm Pollution in China

Holger Görg1, Lars Hecker1, Finn Ole Semrau1, Zheng Wang2

1Kiel Institute for the World Economy, Germany; 2School of Business, University of Dundee

Discussant: Jasper Paul Röder (University of Hamburg (UHH))

China's emergence as the world's leading exporter has placed it at the center of global trade, yet it also faces significant environmental challenges as the largest global polluter. Utilizing granular firm-level data from the Chinese Industrial Enterprise Dataset (CIED), the Chinese Enterprise Pollution Dataset (CEPD) and the Chinese Customs Dataset (CCD), we analyse the relationship between foreign ownership, international trade, and firms' environmental performance.

We find that foreign firms increase pollution reduction efforts downstream, while domestic firms reduce abatement along the value chain. Given that most pollution occurs upstream, this raises concerns about FDI’s environmental impact. Our findings highlight the role of GVC dynamics in shaping corporate environmental behavior, offering insights for sustainable global trade policies.



The evolution of horizontal and vertical air pollution inequalities across Europe

Jasper Paul Röder1, Björn Bos1, Moritz Alexander Drupp1,2, Piero Basaglia3

1University of Hamburg (UHH), Germany; 2Eidgenössische Technische Hochschule (ETH) Zürich, Schweiz; 3University of Bordeaux, France

Discussant: Lan An (Peking University)

This paper explores the development of PM2.5 pollution disparities in Europe since the beginning of this century. To this end, we track and analyze how regional PM2.5 concentration levels have evolved over time and investigate changes in the distribution of air pollution exposure across and within income groups (verti- cal and horizontal inequality). We document a meaningful improvement in air quality during the past two decades, which is particularly due to improvements in regions that were the most polluted at the beginning of the century. Cleaner regions also experienced notable improvements in air quality, although to a lesser extent. We find that PM2.5 exposure levels are distributed unequally along the income distribution (vertical inequality) which is exceeded, however, by air pol- lution inequality within income groups (horizontal inequality). Both of these inequality measures have remained comparatively constant throughout our study period, with slightly increases in both form of air inequality. By contrast, income inequality has decreased considerably over the time horizon. Our results suggest that Europe has avoided a “pollution-equity dilemma” concerning regional PM2.5 levels, indicating that regional growth did not necessarily lead to more pollution.