Double-difference Method Research Articles

Research on the Green Investment of Traditional Energy Enterprises and Its Effectiveness Under Environmental Regulation

Using data from 188 traditional energy companies listed on China’s A-share market from 2012 to 2023, this study adopts the double-difference method to assess the changes in the green investment of traditional energy companies before and after the implementation of environmental regulation policies in depth and further explores the actual effects and potential risks of green investment on the green transformation of traditional energy companies. This study shows that the environmental regulation policies significantly increased the green investment of traditional energy enterprises, but this increase did not effectively promote the overall green transformation of the enterprises; rather, they became more focused on meeting the current compliance requirements while ignoring the fundamental green technological innovation and production mode change. Further analysis reveals that, as environmental standards continue to rise, the increasing green investment expenditure of traditional energy companies for meeting the standards will continue to outpace the growth in capital inflows of traditional energy companies, resulting in a threat to the financial soundness of the companies in the short term and a significant increase in financial pressure. In the long run, the lack of sustained and stable external financial support for a long period of time will not only constrain the green transformation process of enterprises but may also pose a serious threat to the survival foundation of enterprises and even lead to the elimination of enterprises in fierce market competition.

Can ESG ratings promote corporate greening? --Validation based on the double difference method

Drawing on comprehensive data from China’s A-share listed companies over the 2009 to 2021 period, this study utilizes a multi-period difference-in-differences (DiD) model to investigate corporate green transformation in detail. This approach is innovative in its use of green patent licenses and core green licenses as primary indicators, chosen to accurately assess the degree of transformation in environmental sustainability initiatives. The analysis reveals that the introduction of ESG ratings exerts a significant positive influence on corporate green development, as reflected in marked improvements in these green indicators after ESG ratings are adopted. Such findings underscore the important role of ESG ratings in driving sustainable business practices and provide robust evidence that ESG mechanisms are essential in promoting green transformation across enterprises. Based on these insights, it is recommended that governmental bodies intensify the promotion and implementation of green financial policies, which would offer more substantial policy backing for enterprises striving toward green and sustainable growth.

INTERPRETING FAULT DYNAMICS IN TERMS OF HYPOCENTER RELOCATION AND FAULT CHARACTERIZATION

Southeast and Central Sulawesi are the areas characterized by high tectonic activity due to the presence of the active Matano fault. The seismicity along this fault is high. However, the initial hypocenter often deviates from the fault’s trend line, thus causing the need for earthquake relocation with an improved local structure description. The double difference method stands out as a precise technique for hypocenter relocation, utilizing the data on relative travel time between hypocenter pairs. After relocation, the selected hypocenter facilitates the derivation of a focal mechanism, crucial in determining fault types. In this research, we relocated the hypocenters of 485 events of January 2009 to December 2016, ranging in magnitude from M2 to M6.1, 427 of which showed a pattern close to the general trend of major and minor faults. Seismic offsets along the Matano fault are predominantly oriented in the southeast or northwest direction. Moreover, most of the earthquake activity recorded at a depth of 10 km before relocation is no longer visible. Based on the statistics, the time residuals from –2.5 to +2.5 ms resulting from the relocation procedure are better close to 0 than those of –4.5 to +4.5 ms for the events before relocation. The focal mechanism solutions of 16 events of final relocation are dominated by strike-slip faulting. The Matano fault is predominantly sinistral-type. The seismicity along this fault zone results from an activity of this fault, which is the main source of earthquakes, and from its interaction with the neighboring Palu-Koro and Sorong faults.

Double-Pair Double-Difference Relocation Improves Depth Precision and Highlights Detailed 3D Fault Geometry for Induced Seismicity in Alberta, Canada

Abstract Precise earthquake locations with well-constrained uncertainties can improve our understanding of faulting. Double-difference relocation methods, particularly event-pair double-difference relocations, are well established and have been applied to large earthquake catalogs to provide fault geometries. Previous adaptations of the event-pair double-difference method include data space extensions to use additional information from station pairs, referred to as double-pair double-difference relocation. We apply double-pair double-difference relocation to data from a dense network of borehole geophones for induced seismicity monitoring. This experiment was acquired in an area with strong lithological variation and sharp velocity contrasts, and most previous studies using this dataset are subject to poorly constrained focal depths. We compare the double-pair double-difference to event-pair double-difference relocations and study the effectiveness and uncertainties of both methods. Although double-pair double-difference relocation does not improve absolute locations, substantially improved relative locations and reduced uncertainties are obtained. The method reduces the impact of path effects in the source region, which is essential for applications where reservoir units in the source region can exhibit strong velocity contrasts, anisotropy, and fractures. From the improved relocation, we produce a detailed 3D fault interpretation of the dataset that constrains the geological interpretation. The improved catalog shows excellent depth constraints with seismicity that is restricted to specific geological units. We interpret that seismicity activated pre-existing faults in the reservoir layer and adjacent units. Notably, the results show no evidence of induced seismicity activating basement structures.

The Impact of “Smart City” Pilot Construction on China’s Export Product Quality

Based on the double difference (DID) method, this study examines the impact of "smart city" pilot policies on the quality of export products in Chinese cities. Using data from three batches of smart city pilot cities from 2012 to 2014, the results show that smart city construction significantly improves the quality of export products in Chinese cities. It is found that smart city construction achieves a positive impact on export product quality through the paths of promoting technological innovation, upgrading informatization and optimizing resource allocation. In addition, the results of the heterogeneity analysis show that this policy effect is more significant in cities with a developed economy and a higher degree of openness to the outside world. The research in this paper provides empirical support for the formulation of smart city policies and offers policy suggestions for enhancing the export competitiveness of cities.

Green Finance, Economic Policy Uncertainty, and Corporate ESG Performance

Given the increasing prevalence of global warming and the frequent occurrence of extreme weather events and other challenges, countries are increasingly recognizing the importance of green and sustainable development. This paper uses the multi-period double difference and PSM-DID method to test the impact of green finance policies on the ESG performance of Chinese listed companies. Research has shown that implementing pilot zone policies can improve corporate ESG performance, especially for enterprises with low business reputations, fierce industry competition, severe information asymmetry, and state-owned attributes. The GFPZ policy drives companies to improve their ESG performance through two paths: promoting environmental innovation and strengthening restrictions on corporate financing. In addition, the increase in economic policy uncertainty hinders the positive impact of GFPZ policies on improving corporate ESG performance. This study enriches the existing micro-research on green finance policies from the perspective of enterprises. It provides empirical evidence and research insights to support the further improvement of pilot zone policies, the promotion of green sustainable development, and the improvement of corporate ESG performance.

Can Open Government Data Improve City Green Land-Use Efficiency? Evidence from China

This study adopted the double difference method to study the effect of open government data (OGD) on city green land-use efficiency (CGLUE). It was found that opening government data had a significant promotional effect on CGLUE, and a number of robustness tests were the foundation for this finding. A mechanism analysis demonstrated that two key avenues via which government data openness can promote CGLUE are raising public awareness of environmental issues and strengthening urban green innovation potential. A heterogeneity analysis found that the effect of government data openness on CGLUE was more obvious in eastern cities, cities with higher levels of digital finance, and non-resource-based cities. In addition, open government data also reduced urban carbon emissions while improving CGLUE, contributing to China’s “double carbon” goal.

The Effects of Big Data Regulations on Industrial Modernization in Resource-Based Cities: A Semi-Natural Study Using a State-Level Big Data Coordination Zone

As a core component of the digital economy, big data provides resource-based cities with a new impetus for upgrading their industrial structures. This paper employs a double difference method with panel data from 86 resource cities in China from 2009 to 2020 in order to investigate the effects of big data policies on resource cities' upgrading of their industrial structures objectively. Quasi-control groups are the quasi-natural trials of two batches of 19 resource cities in national big data comprehensive experimental zones. The empirical results demonstrate that the nationwide comprehensive experimental zone for big data exerts a considerable influence on the industrial upgrading of resource-based cities. This conclusion remains robust even after putting it through a series of tests, including the consolidation test and the stability test. Ultimately, this study offers a novel approach to catalyzing industrial upgrading in a big data context, shedding light on crucial issues such as economic instability in resource-based cities.

The Impact of The "Dual Carbon" Target on China's Coal Industry Stock Prices--Analysis Based on The Double Difference Method

The proposal of "dual-carbon" target has far-reaching impacts on the coal industry and its stock market. This paper takes the data of China's A-share coal listed companies in Shanghai and Shenzhen from 2018 to 2023 as samples, takes the proposal of "dual-carbon" target as an exogenous event, and uses double-difference model to conduct regression analysis to study the impact of "dual-carbon" target on the stock price of China's coal industry. The results show that the introduction of the "dual carbon" target has a significant negative impact on the stock price of China's coal industry, and the results are still significant after the parallel trend test, the placebo test, and the test of excluding the year of policy promulgation. Based on this, recommendations are made for the government, regulators, coal industry enterprises and investors to jointly promote the development of the "dual-carbon" policy and the transformation and upgrading of the coal industry.

Relocation of the 8 September 2023 High Atlas, Morocco, Earthquake Aftershock Sequence

ABSTRACT The earthquake that occurred on 8 September 2023, with a magnitude of 6.8, was the most destructive earthquake event in Morocco in the past decade. This earthquake took place in the Al Haouz region, located in the western part of the High Atlas Mountain range. To better understand what caused and triggered this earthquake, the earthquake catalogs including P and S arrival times were collected from the Moroccan seismic network and combined with regional data from the International Seismological Centre. The mainshock and aftershocks were relocated by using iLoc, a state-of-the-art single-event location algorithm, and then by the multiple event location double-difference algorithm, hypoDD. The improved earthquake relocations using iLoc and the double-difference methods provide sharper lineation of seismicity and agree well with tomographic images of the earthquake zone. The seismicity distribution and the focal mechanism of the mainshock indicate that the earthquake sequence has occurred along the South Atlas fault system.

Quasi-real-time earthquake relocation and monitoring in the northeastern Noto Peninsula

The seismicity rate markedly increased in the northeastern Noto Peninsula of Ishikawa Prefecture around the end of 2020, with an Mw6.2 event on 5 May, 2023, followed by many aftershocks. Previous earthquake relocation studies have detected upward migration of microearthquakes via multiple faults and clusters, suggesting the involvement of crustal fluids in this sequence. Since some active faults exist near the source region, there was concern that this sequence could lead to a larger earthquake; it became a reality with the Mw7.5 earthquake on 1 January 2024. This study aims to develop an algorithm to precisely relocate microearthquake hypocenters in quasi-real time for better monitoring. A fine view of seismicity requires relative relocation methods such as the double-difference (DD) method with numerous arrival time difference data precisely measured by the waveform correlation analysis. However, the standard DD method has the disadvantage of huge computational costs when data increase, making it unsuitable for real-time monitoring in such situations. We developed a quasi-real-time algorithm that relocates only new earthquakes using the DD method each time a new time window of data is added. The major improvement is that our method incorporates a traditional simple relative relocation and preserves constraints between different time windows; the relative locations of new events are constrained from reference events that were already relocated in the previous time windows. We tested a daily relocation algorithm on 11,546 events from 19 June, 2022, to 31 May, 2023, in the Noto Peninsula earthquake sequence. We found that our modification substantially reduced artificial hypocenter offsets between different time windows and succeeded in resolving the fine fault structures from the cloud-like distribution of initial hypocenters. If we do not impose constraints between different windows, the relocated hypocenters are scattered and do not show fine planar structures. Our algorithm greatly reduces the computational cost, allowing for quasi-real-time earthquake relocation and monitoring. We hope this algorithm will help monitor the spatio-temporal distribution of future earthquake sequences.Graphical

The impact of socialisation services in the whole process of agricultural production on food security—quasi-natural experimental evidence from China

Food security (FS) is an important guarantee for world peace and development and the basis for building a community of human destiny, which has a bearing on the sustainable development and future destiny of humankind. This study empirically analysis the relationship between socialisation services in the whole process of agricultural production (ASS) and guaranteeing FS, as well as the path of their role, using provincial panel data from 2010 to 2022 in China as an example, using the double-difference method. The regression results show that ASS can have the ability to contribute to the level of FS, and the conclusion still holds after a series of robustness tests. The results of the heterogeneity analysis show that the role of ASS in guaranteeing FS receives the influence of the level of agricultural development in each region, while it plays a greater role in the main food-producing areas. The mechanism analysis analyses the mechanism of the role of ASS in the whole process of agricultural production in guaranteeing FS from the three links of pre-production, mid-production and post-production respectively, and finds that ASS in the whole process of agricultural production is able to guarantee FS by reducing the cost of purchasing means of production in the pre-production stage, fostering a new type of agricultural management main body in the mid-production stage, and increasing the income of farmers’ household management in the post-production stage. Based on the above findings, this study proposes corresponding policy recommendations. This study can provide insights for ensuring world FS and contribute to maintaining social stability and development. The conclusions of the study are universally applicable, and all countries in the world can benefit from and draw lessons from it.

The Impact of the National Civilized City Program on the Environmental, Social and Governance Performance of Enterprises: Evidence from China

The National Civilized City Program is an important governance championship for cities in China. Taking the National Civilized City Program as a quasi-natural experiment, based on the data of A-share listed companies in Shanghai and Shenzhen from 2009 to 2021, the multi-period double-difference method is used to investigate the impact, mechanism of action and heterogeneity of the National Civilized City Program on corporate ESG performance. It is found that the National Civilized City Program can significantly enhance corporate ESG performance, and this conclusion still holds after a series of robustness tests. The National Civilized City Program improves corporate ESG performance through two channels: strengthening environmental regulation and promoting the fulfillment of corporate responsibility towards employees. There is significant heterogeneity in terms of geography, firm ownership and pollution attributes in the impact of the National Civilized City Program on firms’ ESG performance.

Can E-Commerce Policies Drive Common Wealth Levels —— A Study Based on County-Level Data in China, 2012-2020

Based on national county panel data from 2012 to 2020, this study systematically examines the impact of the comprehensive e-commerce into rural areas demonstration project implemented in rural China on promoting the level of common wealth by applying the multi-period double-difference method (DID). It is found that the e-commerce policy significantly enhances the level of common wealth. Further analysis of the impact mechanism shows that the policy effectively promotes the goal of common prosperity by enhancing the level of rural employment. In addition, the positive effect of the e-commerce policy is strengthened by the increase in the level of local government fiscal expenditure, however, the driving effect of the policy is weakened by the higher level of social consumption. Heterogeneity analyses indicate that the policy's promotional effect is particularly significant in the demonstration counties of the Yangtze River Economic Belt. This paper fills the research gap on the relationship between rural e-commerce policy and the level of common wealth, and provides empirical evidence and policy recommendations for related policy formulation.

Impact Study of Environment Public Interests Litigation on Carbon Emissions: Taking Pilot Policy of Procuratorial Public Interest Litigation as a Quasi-Natural Experiment

The environmental problems caused by carbon emission have become the focus of worldwide attention. Effective control of carbon emissions cannot be achieved without the protection of the rule of law. Environment public interests litigation is a prominent innovation in the judicial system, and its role in supervising the government to perform its regulatory duties on carbon reduction and regulating the carbon emission behaviors of enterprises and the public deserves discussion. The paper selected the panel data from 274 prefecture-level cities from 2013 to 2021 and analyzed the impact of a procuratorial public interest litigation pilot policy on carbon emission control by using the double difference method. The research found that the procuratorial public interest litigation pilot policy can effectively curb carbon emissions. Heterogeneity analysis showed that in cities with relatively low level of green innovation, the negative correlation between procuratorial public interest litigation pilot policies and carbon emissions is more significant. Compared with the eastern region, in the central and western regions, especially in the central region, where the concept, policy, and funding of carbon emission governance are relatively weak, the implementation of the pilot policy of procuratorial public interest litigation had a more obvious effect on carbon emission governance. Mechanism tests showed that procuratorial public interest litigation policies reduce carbon emissions by reducing energy consumption and increasing public participation in environmental protection. The study will provide an empirical basis for the carbon emission reduction effect on pilot policy of procuratorial public interest litigation and will offer certain theoretical recommendations for improving the procuratorial public interest litigation system in the ecological environment field.

3-D P-wave velocity structure of the upper mantle beneath eastern Indonesia from body wave tomography

Eastern Indonesia's tectonic setting is well known for its complexity and intense seismic activity. Controlled by several major and minor plates, including the Eurasian, Australian, and Pacific plates, this region is famous for its U-shaped subduction system beneath the Banda Arc. To better understand the architecture of the underlying structure in this region, we performed body-wave travel time tomography using ten years of catalog data provided by the Indonesian Agency for Meteorology, Climatology, and Geophysics. We utilize 9729 events in total, from which 46,446 P-wave arrival times were extracted. We used a double difference method to relocate the initial event catalog, which produced a pattern of seismicity consistent with a curved subduction system. Our tomographic model reveals a high velocity band between 90 and 240 km depth in the upper mantle, which is interpreted to be a concave dipping lithospheric slab that is parallel to the present-day Banda arc. Our results also show that lithosphere subducting from the north and south starts to collide at a depth of 300–350 km and becomes shallower further east. Apparent discontinuities in the high velocity band and a corresponding lack of seismicity supports the presence of a slab tear to the west of Seram. A dipping high velocity structure that is present from south to north beneath the island of Timor represents a subducting slab that dips more steeply beyond a depth of 150–200 km, which appears consistent with slab roll-back. Our tomographic model also shows evidence of back arc thrusting to the north of Sumbawa and Flores Islands in the form of a south-dipping higher velocity band at shallow depth. Furthermore, our tomographic models also reveal the possible presence of underthrust continental forearc in the form of a thin higher velocity anomaly that connects the backarc thrust and northward dipping lithosphere slab in the Timor area. Finally, a zone of low velocity above the higher velocity slab is clearly seen beneath Seram Island at a depth of ∼100 km and may represent a partial melting zone.

Relocation of Earthquakes Hypocenter Using the Double Difference Method in Bali and Its Surrounding Areas

A study on the relocation of earthquake hypocenters using the Double Difference method has been conducted in Bali and its surrounding areas. This research was carried out at the Center for Meteorology, Climatology, and Geophysics Region III Denpasar. The purpose of this study is to find out the distribution of earthquake hypocenters before and after the relocation and to know the continuity of earthquake hypocenters in the Bali region. The data used are arrival time data of 1,815 earthquake events from January 1, 2014 to December 31, 2023, and data from 26 earthquake recording stations. The relocation method applied is the Double Difference method, which is processed with ph2dt and HypoDD. The relocation that has been carried out shows a good hypocenter position which is characterized by a residual value of travel time that is close to 0. The distribution of the earthquake hypocenter in the Bali area before the relocation spread throughout the region and after the relocation, the position of the hypocenter was getting closer to the source of the earthquake, namely in the subduction zone under the Bali area as shown in the cross-section results. In addition, based on the results of the analysis of the hypocenter of the earthquake after relocation, it was found that the trend of the hypocenter continued toward the subduction subduction zone.

Does the Innovative City Pilot Policy Promote Urban Energy Use Efficiency? Evidence from China

The innovative city pilot policy (ICPP) is a key policy practice in China’s innovation-driven economic strategy, yet its influence on urban energy use efficiency (UEUE) has yet to be assessed. This study used balanced panel data from Chinese cities from the period of 2006 to 2022 to investigate the impact of innovative cities on urban energy consumption efficiency. The double-difference method, which treats creative cities as quasi-natural experiments, was applied to identify the impact mechanism of these cities. Additionally, this study looked at heterogeneity from several angles and assessed the effects of the policy on the environment. Following thorough testing to guarantee the reliability of the findings of this study—such as changing variables, ruling out further policy interferences, and running placebo tests—it can be concluded that the pilot program significantly improves urban energy consumption. The mechanism analysis performed in this study shows that, via talent concentration, utilizing technology, and optimizing the industrial structure, the creative city pilot policies increase energy consumption efficiency. Additionally, a heterogeneity analysis shows that eastern cities and cities with a high degree of digital finance benefit most from the legislation in terms of energy consumption efficiency. The application of creative city pilot programs has a more noticeable effect on increasing the energy consumption efficiency in eastern cities, as well as in cities with a high degree of digital infrastructure and digital finance, according to the heterogeneity analysis. Furthermore, an environmental consequence test shows that, by encouraging the growth of UEUE, the development of innovative cities can successfully help to reduce carbon emissions.

Assessing the impact of free trade agreement (FTA) signing on China’s outbound labor services

This study utilizes panel data encompassing 164 countries to analyze China’s foreign labor export from 2008 to 2017. Employing the multi-period double-difference method, the research investigates the impact of Free Trade Agreement (FTA) signings on China’s labor export. Empirical findings reveal the following insights:The signing of FTAs significantly enhances China’s foreign labor export, demonstrating a temporal effect. Importantly, this conclusion withstands rigorous testing through various robustness checks. FTAs have a positive impact on China’s labor export to developing countries but do not exhibit a similar effect on developed countries. The impact of FTAs on labor export is pronounced in contractual engineering scenarios, while no discernible effect is observed in China’s labor cooperation. Through a meticulous examination of specific WTO+ and WTO-X provisions, the study underscores that it is primarily the WTO+ provisions that drive China’s foreign labor export. Consequently, strategic recommendations are proposed. These include fostering additional FTAs between China and developing nations, prioritizing labor export within contracted projects, encouraging expansion of Chinese labor export enterprises into new markets, promoting multi-party cooperation to facilitate overseas labor export, diligent consideration of existing FTA provisions, and exploration of transitioning from WTO+ to WTO-X provisions.

Do Green Finance Policies Inhibit the Financialization of Manufacturing Enterprises? Empirical Evidence Based on a Quasi-Natural Experiment with the “Green Credit Guidelines”

Against the background of the increasing financialization of manufacturing enterprises, whether green financial policies can inhibit the financialization of manufacturing enterprises is a major practical issue worth exploring. It can help government departments to guide the sustainable development of the real economy of enterprises, effectively curbing the trend of over-financialization of enterprises, thus preventing potential systemic risks and safeguarding the sustainable development of the economy. Because the green credit guidelines function as a more mature development of green financial policies, this paper takes Chinese A-share listed companies from 2005 to 2022 as the research sample, adopts the propensity score matching and double difference method, and constructs a quasi-natural experiment with the “Green Credit Guidelines” as the policy shock to analyze the multiple impact effects of green financial policies on the financialization of manufacturing enterprises. The results of the study show that (1) green finance policy has a significant inhibiting effect on the financialization of manufacturing enterprises; (2) due to the different motives of manufacturing enterprises in holding financial assets, green finance policy has a more significant inhibiting effect on the long-term financialization of “substitution”; (3) state-owned enterprises (SOEs) bear more social responsibilities and have credit advantages. Green finance policy has a more obvious inhibiting effect on the financialization of non-state-owned manufacturing enterprises; (4) major shareholders can play a better supervisory role in enterprises with high equity concentrations, so green finance policy has a more significant inhibiting effect on the financialization of manufacturing enterprises with low equity concentrations; (5) financing constraints have a masking effect in green finance policy and enterprise financialization. Based on this, this paper puts forward the following targeted recommendations. For the governmental level: first, to establish a sound manufacturing credit system; second, to focus on enterprise-financing constraints. For the enterprise level: first, to optimize the asset structure to promote transformation; second, to deepen the mixed ownership reform of state-owned enterprises.