Page 71 - Read Online

Page 4 of 16 Hu et al. Carbon Footprints 2024;3:16 https://dx.doi.org/10.20517/cf.2024.28

areas. This indicates a need to take into account urban growth alongside industrial park development when
[27]
devising carbon emission reduction strategies .
In addition, there are also other types of national-level industrial parks, such as LCIP, which started to be
approved and certified in 2014. The impacts of these parks on urban industrial carbon emissions, as well as
the differences in the effects between these types of parks, remain to be further studied. Moreover, China
has introduced a series of policies to promote the transformation and upgrading of industrial parks and
introduce green cycling, which may help reduce carbon emissions as well. It is thus desirable to further
examine the type-specific impacts of industrial parks on city carbon emissions and the inter-type
differences. This may help understand the effectiveness of national-level industrial park policies and provide
policy insights for the application for and the approval of industrial parks.

Given the above, this study uses data from 204 cities at or above the prefecture level in China from 1999 to
2019 and applies the DID method to examine the impact of three types of industrial parks on urban carbon
emissions, namely, economic and technological development zones (ETDZ), eco-industrial demonstration
parks (EIDP), and low-carbon industrial parks (LCIP). Specifically, the carbon reduction effects and
dynamic paths of these industrial park policies are first explored. Second, the mediating effects are analyzed,
with policy levers of carbon reduction clarified. Third, the heterogeneity in the effects with respect to a city’s
geographical region, resources endowment, and the amount of relevant industrial parks, as well as their
spatial spillover effects, are studied.

The main contribution of this study is that it looks into the type-specific effects of national industrial park
policies on city carbon emissions, taking into consideration different implementation timing, locations, and
policy emphases. In particular, this study contributes to analyses of ETDZs and LCIPs, deriving analogies
and contrasts for the impacts of three different types of industrial parks.

METHODOLOGY
Research framework
Figure 1 provides an overview of the study’s analytical framework, demonstrating the connection between
industrial park policies studied, the models employed, and the subsequent empirical analyses of the effects
on city carbon emissions.

Model specification
Benchmark model
The DID method, widely used for examining policy effects, is employed in this study. The Difference-in-
Differences (DID) methodology is a robust and widely used technique for causal inference, especially in
policy evaluation and impact studies. In this study, DID was chosen to assess the causal impact of the
construction of different types of industrial parks (ETDZ, EIDP, and LCIP) on urban carbon emissions. The
rationale for selecting DID is based on its ability to compare changes over time between a treatment group
(cities with industrial parks) and a control group (cities without industrial parks), thereby isolating the
effects of industrial park policies on carbon emissions. Herein, cities with the parks under study are set as
the treatment group, while cities without set as the control group.

The benchmark model is as follows in Eq. 1.

CARBON = α + β * TREAT + θ * CONTROL + γ + μ + ε (1)
t
i
i,t
i,t
i,t
i,t