Efficiency Gap Research Articles

Understanding the role of the government in promoting various sustainability sub-systems: An analysis based on new parallel-series network data envelopment analysis models

Sustainability has been a global consensus for the governments worldwide to address serious environmental issues. However, there is a lack of data envelopment analysis (DEA) studies evaluating the performance of government in promoting various sustainability sub-systems. To do this evaluation work, our study proposes new parallel-series network DEA models with alternative network structures of incorporating intermediate products. Particularly, this study develops a new methodological framework to evaluate various inefficiency sources. The framework contains an extended method of network meta/group frontier approach and a new concept of efficiency Foster-Greer-Thorbecke indicator. Empirically, this study considers the case of Chinese government-sustainability system from 2010 to 2017. Such work cannot be found in the existing studies. The main findings are summarized as follows. First, China has succeeded in realizing an overall improved efficiency during the examined periods. The importance of various divisions changes over time. Second, the occurrence of method heterogeneity and significant linkage inefficiency implies that the modelers should incorporate intermediate products in a well-suited way. Finally, inland provinces show higher technology gap inefficiency as for economy division. To improve the performance, inland provinces should promote their human capital and adopt advanced technology.

Unearthing marine ecological efficiency and technology gap of China’s coastal regions: A global meta-frontier super SBM approach

With the promotion of the maritime power strategy and progressively increasing and severe environmental problems, marine ecological efficiency is fast becoming an essential object of research in achieving sustainable development. By applying the meta-frontier super SBM model and the global Malmquist-Luenberger index, this paper aims to explore the marine ecological efficiency of coastal regions in China and the technology gaps between different regions during 2006–2017. On this basis, the changes in marine ecological efficiency were decomposed to investigate the driving factors. The results indicate that the marine ecological efficiency of China’s coastal regions was still ineffective, and there was a significant gap between the group production technology and the potential optimal production technology. Also, there was a significant regional technological heterogeneity. The Yangtze River Delta region had optimal production technology level, while the Beibu Gulf region distinctly had a sizeable technological gap with the other three regions. Besides, the primary factor affecting marine ecological efficiency was technological progress. Finally, the results of this paper passed the robustness check. Based on these conclusions, some specific policy suggestions are provided for China’s coastal regions.

Evaluating efficiency and technology gaps of the national systems of entrepreneurship using stochastic DEA and club convergence

Evaluating efficiency and technology gaps of the national systems of entrepreneurship using stochastic DEA and club convergence

Spatio-temporal efficiency of fiscal environmental expenditure in reducing CO2 emissions in China's cities

Although market-based CO2 emission control measures (e.g., carbon tax and carbon trading market) have been deeply discussed, government-based measures have received limited attention. This has led to increased uncertainty regarding the formulation of targeted emission reduction policies. Using a unique dataset, the non-radial directional distance function, a proposed spatial meta-frontier analysis method, and the log t convergence model, this study comprehensively investigates the spatio-temporal trends in fiscal environmental expenditure efficiency (FE) and corresponding causes for in a case study for 106 Chinese cities over 2007–2019. The results show that city-level FE presented a slow upward trend at a relatively low level, with a clearly skewed distribution. The technology gap effect between city groups and the overall best production technology, and the efficiency gap effect within city groups were the main drivers widening the overall FE gap. Convergence analysis indicated that three convergence clubs of FE were found, which were distributed across the country. This study highlights that, when constructing fiscal environmental expenditure policies, the government should focus on balancing the regional gap of FE while comprehensively improving FE.

The history of energy efficiency in economics: Breakpoints and regularities

Taking a long-run historical perspective, we analyze how debates about energy efficiency have evolved in the economic literature since the mid-19th century. We distinguish three periods: the classical age, focused on the rebound effect, from Jevons in the 1860s to American institutionalism in the mid-20th century; the modern age, marked by the rise of the energy efficiency gap concept, from the 1970s to the 1990s; the contemporary age, from the early 2000s onwards, focused on the concept of energy performance gap. We find that reflections on energy efficiency have embraced more general developments in the economics discipline: emergence of institutionalism in the classical age, primarily concerned with policy; public economics in the modern age, emphasizing the concept of market failure; behavioral economics and the so-called credibility revolution in empirical economics in the contemporary age, which made energy efficiency a much-favored context for conducting experiments, questioning rationality and implementing nudges. The transitions between phases closely paralleled changes in societal concerns, from resource depletion in the classical age to energy security in the modern age to climate change in the contemporary age. Throughout this long history, we have detected a change in focus from macro- to micro-perspectives. Despite increasing sophistication and constant reinterpretation, energy efficiency remains a subject of controversy, such that no consensus has yet been reached on its potential and effective benefits. In closing, we propose to update Jaffe, Newell and Stavins' landmark energy efficiency gap framework to account for the most recent developments and trace avenues for future research.

Bioenergy for Community Energy Security in Canada: Challenges in the Business Ecosystem

Bioenergy represents a viable renewable alternative for the many off-grid remote communities in Northern Canada that rely on diesel-based energy infrastructure. Despite the abundance of forest-based biomass, bioenergy for heat and power in Canada is used primarily in industrial contexts. Community-scale bioenergy, although growing, has been limited. Supply chain challenges, institutional and policy arrangements, and community perspectives indicate a need to better understand the ‘business ecosystem’ for bioenergy in Canada. The ecosystem includes technologies, community contexts, suppliers, developers, and policy makers. In this study, we explore the bioenergy business ecosystem challenges and perspectives from supply-side stakeholders. Interviews were conducted with representatives from the government, industry, and community—all working in bioenergy. The results indicate the following challenges facing the bioenergy ecosystem, with respect to community energy security: lack of cross-jurisdictional consistency in legislation and policies across Canada, structural issues such as subsidized energy and utility ownership, and misdirected support for local capacity building in the bioenergy sector. We also find that the existing support systems are prone to misuse, pointing to efficiency gaps in investment flows. The insights that emerge from this work, especially from industry stakeholders, are meaningful for communities and policy makers alike.

Analyzing technical efficiency in Vietnamese seafood processing firms: A semi-parametric stochastic frontier approach

This research aims to estimate and analyze the technical efficiency of Vietnamese seafood processing firms by applying the semi-parametric stochastic frontier model and Tobit regression. The data used in this study is a panel sample of 170 Vietnamese seafood processing firms in the period from 2013 to 2018. It is collected from enterprise census data of the General Statistics Office of Vietnam and provincial competitiveness index data of the Vietnam Chamber of Commerce and Industry. The estimated results show that: The scores of technical efficiency of firms averaged 0.712 and there was a decline during the study period. There is still plenty of room for technical efficiency in firms; The gap in technical efficiency in firms is still large and there is a strong difference in efficiency between firm’s ownerships and firm sizes; Firms with export activities, large scale, foreign direct investment capital, and low equity restrictions will have a positive impact on technical efficiency; However, there is no evidence to show the impact of the firm’s age and firm located in industrial zones factors on the efficiency of firms. In addition, the institutional quality and business environment also have an impact on the performance of firms.

Valuations of charging efficiency and critical gap for electron tunnelling under contact electrification model

Valuations of charging efficiency and critical gap for electron tunnelling under contact electrification model

Carbon emission reduction policy with privatization in an oligopoly model.

This study constructs a mixed oligopoly model that includes a public enterprise and two private enterprises. Game theory was adopted to explore the effects of carbon emission reduction policies. In addition, this study analyzes the optimal carbon emission trading prices and privatization decisions. The results show that the proportion of state-owned shares and the equity efficiency gap affect the equilibrium results for different carbon emission policies. Privatization increases the profits of public firms but does not necessarily increase social welfare. Different carbon emission reduction policies have different effects on the equilibrium results. Moreover, the emission reduction target is not completely consistent with the maximum social welfare target and should be comprehensively considered. The government can intervene by setting carbon emission trading prices and making privatization decisions. Full and partial privatization may be optimal decisions.

Carbon-adjusted efficiency and technology gaps in gold mining

Carbon-adjusted efficiency and technology gaps in gold mining

Farm economic efficiency gap due to gender discrimination-evidence from USAID markets II Programme participating small-scale farmers in Kano state of Nigeria

Farm economic efficiency gap due to gender discrimination-evidence from USAID markets II Programme participating small-scale farmers in Kano state of Nigeria

Limiting Performance of the Ejector Refrigeration Cycle with Pure Working Fluids

An ejector refrigeration system is a promising heat-driven refrigeration technology for energy consumption. The ideal cycle of an ejector refrigeration cycle (ERC) is a compound cycle with an inverse Carnot cycle driven by a Carnot cycle. The coefficient of performance (COP) of this ideal cycle represents the theoretical upper bound of ERC, and it does not contain any information about the properties of working fluids, which is a key cause of the large energy efficiency gap between the actual cycle and the ideal cycle. In this paper, the limiting COP and thermodynamics perfection of subcritical ERC is derived to evaluate the ERC efficiency limit under the constraint of pure working fluids. 15 pure fluids are employed to demonstrate the effects of working fluids on limiting COP and limiting thermodynamics perfection. The limiting COP is expressed as the function of the working fluid thermophysical parameters and the operating temperatures. The thermophysical parameters are the specific entropy increase in the generating process and the slope of the saturated liquid, and the limiting COP increases with these two parameters. The result shows R152a, R141b, and R123 have the best performance, and the limiting thermodynamic perfections at the referenced state are 86.8%, 84.90%, and 83.67%, respectively.

Technology gap ratio decomposition in sugarcane farming in Indonesia

Indonesia's population and income growth have led to a higher demand for raw sugar and its derivative products; for this reason, sugarcane production must be improved, especially in central production areas. However, efforts are constrained by the disparity in resource endowment and technology. This study aimed to analyse technical, technological, and managerial gaps in sugarcane farming in different areas of East Java. The study used primary data collected through a survey during the 2019/2020 sugarcane planting season in Malang, Kediri, and Mojokerto Regencies. A structured questionnaire was used to collect data on inputs and outputs. A meta-frontier data envelopment analysis (meta-DEA) approach was used to measure the technical efficiency of sugarcane farming in each research area. The decomposition using meta-DEA showed that, on average, the meta-technical inefficiency of sugarcane farmers was caused mainly by managerial gaps, as the average managerial gap inefficiency (MGI) was more significant than the technological gap inefficiency (TGI). Malang regency showed the largest TGI and MGI, indicating that sugarcane farmers in Malang regency have lower managerial skills for decision-making and a lower level of production technology compared to the other two regions. Based on the findings of this study, the government should improve technological innovation to mitigate the technology gap that was found in our research location.

New Pathways toward Sustainable Sn‐Related Perovskite Solar Cells

Sn‐related perovskite solar cells (PSCs) have emerged as one of the most promising lead‐free, environmentally viable photovoltaic technologies. Recent years have witnessed rapid development in terms of soaring photovoltaic performances of Sn‐related PSCs, progressively narrowing their power conversion efficiency (PCE) gaps to the Pb‐based counterparts. However, further enhancement of PCE and lifespan are largely limited by the easy oxidation of Sn2+ and by‐products‐induced defects. Beyond the stereotyped antioxidation strategies using reducing agents, in this perspective, several novel chemical pathways, which are able to simultaneously boost the PCE and stability of Sn‐related PSCs, are summarized and highlighted. In addition, the impact of molecular design on the antioxidation, de‐doping, defect passivation effect, and other optoelectronic properties of Sn‐based perovskite films and devices is elucidated. Last but not least, associated challenges and future research directions are also discussed and proposed for fabricating efficient, stable, and sustainable Sn‐related optoelectronic devices.

Dynamic evaluation of ecological and economic security: Analysis of China

As the contradiction between ecological protection and socioeconomic development continues to intensify, the balanced development of economy, resources, environment, and society has become a core issue in promoting the achievement of high-quality development. In this study, we proposed a framework for assessing China's ecological and economic security, from the perspective of national sustainable development. We also assessed the level and dynamic evolution pattern of the ecological and economic security of different provinces and regions, in terms of the dynamic characteristics of sustainable development. The results indicated that from 2005 to 2019, China's ecosystem sustainability level did not improve significantly, with prominent regional differences; notably, the country would need to deplete its natural capital stock for economic development. As of 2019, China achieved comprehensive and stable high-quality socioeconomic development, but there was a wide gap in the eco-economic efficiency of individual provinces. Currently, the efficiency of the use of natural capital needs improvement. In terms of the ecological and economic security of China's provinces, only the coastal economic zone maintained a safe level of ecological economy, while the rest of the provinces portrayed fluctuations. The convergent evolution of the state revealed that the ecological and economic security portrayed an overall upward trend. However, after considering the neighborhood effect, the ecological and economic security of the northern and southern regions increased, whereas that of the central and coastal regions decreased. This study can serve as a viable framework, to promote sustainable development in not just China, but also other global economies.

Design Challenges in Hydrogen-Fueled Rotary Engine—A Review

The rotary engine (RE) is a potential power plant for unmanned aerial vehicles (UAVs) and automobiles because of its structural and design merits. However, it has some serious drawbacks, such as frequent maintenance requirements and excessive fuel consumption. This review paper presents the current status of hydrogen-fueled rotary engine (HRE) technology and identifies the existing research and development gaps in combustion efficiency and performance of this engine that might benefit transportation sector. Focusing primarily on the research from past ten years, the crucial challenges encountered in hydrogen-powered rotary engines have been reviewed in terms of knock, hydrocarbon (HC) emissions, and seal leakages. The paper identifies the recent advances in design concepts and production approaches used in hydrogen-fueled rotary engines such as geometric models of trochoid profiles, port configurations, fuel utilization systems, and currently available computational fluid dynamics (CFD) tools. This review article is an attempt to collect and organize literature on existing design methods up to date and provide recommendations for further improvements in RE technology.

Recent progress of inverted organic-inorganic halide perovskite solar cells

In recent years, inverted perovskite solar cells (IPSCs) have attracted significant attention due to their low-temperature and cost-effective fabrication processes, hysteresis-free properties, excellent stability, and wide application. The efficiency gap between IPSCs and regular structures has shrunk to less than 1%. Over the past few years, IPSC research has mainly focused on optimizing power conversion efficiency to accelerate the development of IPSCs. This review provides an overview of recent improvements in the efficiency of IPSCs, including interface engineering and novel film production techniques to overcome critical obstacles. Tandem and integrated applications of IPSCs are also summarized. Furthermore, prospects for further development of IPSCs are discussed, including the development of new materials, methods, and device structures for novel IPSCs to meet the requirements of commercialization.

Taking stock of gender gaps in crop production technology adoption and technical efficiency in Ghana

ABSTRACT There is a strong linkage between agricultural performance and economic growth in developing countries. However, the gain from agriculture disproportionately trickles down to the poor which can be partly reduced by addressing gender differences in production. Historically, the validity of gender statistics has been questioned as the way researchers and policymakers describe gender differences also affects how they perceive and address them. Amid these antecedents, we apply a meta-stochastic frontier to pooled cross-sectional population-based surveys that represent three decades (1987–2017) of the production history for twelve crops in Ghana to assess the dynamics of gender gaps in technology gaps and technical efficiency (TE). Results indicate that female farmers exhibit technology gap and TE scores of 25 and 76% while their male counterparts exhibit scores of 20 and 73%. The TE gap of 4% against male farmers has remained relatively steady over the three decades while the technology adoption gap against females has reduced from 18% in 1997/98 to 3% in 2016/17. All farmers operate at 60% of the potential possible given the overall crop production technology in Ghana. Over the three decades, the estimated crop production gap of 5.94% against females shifted to a gap estimated at 9.24% against males.

Effects of hollow skeleton on melting process in copper foam

The compositing of porous medium and phase change material is an effective way to improve the heat transfer performance of solid-liquid phase change energy storage system. In this paper, we reconstruct the three-dimensional numerical structure of the copper foam by using the micro computed tomography, and then conduct the pore-scale numerical simulation of the melting process in a cubic cavity filled with the phase change material comprised of the copper foam via the lattice Boltzmann method. The effects of the hollow skeleton on the melting process are discussed in detail under different Rayleigh numbers and ratios of thermal conductivity of the copper foam to that of the phase change material. The results show that the hollow skeleton copper foam possesses a lower average Nusselt number along the left wall at the early stage of the melting process, a slower melting rate, and a higher energy storage efficiency than the solid skeleton copper foam. Comparing with the skeleton region of the copper foam, the heat transfer rate entering the cubic cavity through the hollow region of the skeleton is almost negligible. Because of the competition between heat conduction and natural convection, the heat transfer enhancement efficiency of copper foam first increases, then decreases, and then increases again with the increase of the Fourier number. When the Rayleigh number decreases, the energy storage efficiency increases, and the natural convection also weakens. Meanwhile, the fluctuation of the heat transfer enhancement efficiency decreases as the Fourier number increases, and the gap of the heat transfer enhancement efficiency between the hollow skeleton copper foam and the solid skeleton copper foam becomes smaller. When the ratio of the thermal conductivity of the copper foam skeleton to that of the phase change material increases, the energy storage efficiency is relatively high at the early stage of the melting process but becomes relatively low when the melting process is completed. With a larger thermal conductivity ratio, the heat transfer rate entering the cubic cavity through the skeleton region of the copper foam becomes dominant, which reduces the effect of the hollow skeleton on heat transfer, and thus the gap of the heat transfer enhancement efficiency between the hollow skeleton copper foam and the solid skeleton copper foam becomes relatively small.

The Energy Efficiency Gap in the Rental Housing Market: It Takes Both Sides to Build a Bridge

We revisit the issue of the energy efficiency (EE) gap by explicitly acknowledging the two-sided nature of the rental housing market and two-sided asymmetries of information between tenants and landlords. Employing a theoretical matching model, we show that Energy Performance Certificates (EPCs) that signal a dwelling’s energy performance induce optimal EE investments by landlords only if tenants pay their energy expenditures in full. When landlords pay part of the energy expenditures, they seek tenants who will conserve energy. Our model shows that asymmetry of information over tenant characteristics results in suboptimally low investments in EE. This may even render EPCs counterproductive. As a remedy, we show that tenant-side signaling needs to be rolled out jointly with EPCs and may even be sufficient when contracts include energy expenditures. Data from an original survey provides support for these insights and suggests that information on the tenants’ side contributes to more EE investment.