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71.
In the presence of heteroskedasticity, conventional test statistics based on the ordinary least squares (OLS) estimator lead to incorrect inference results for the linear regression model. Given that heteroskedasticity is common in cross-sectional data, the test statistics based on various forms of heteroskedasticity-consistent covariance matrices (HCCMs) have been developed in the literature. In contrast to the standard linear regression model, heteroskedasticity is a more serious problem for spatial econometric models, generally causing inconsistent extremum estimators of model coefficients. This paper investigates the finite sample properties of the heteroskedasticity-robust generalized method of moments estimator (RGMME) for a spatial econometric model with an unknown form of heteroskedasticity. In particular, it develops various HCCM-type corrections to improve the finite sample properties of the RGMME and the conventional Wald test. The Monte Carlo results indicate that the HCCM-type corrections can produce more accurate results for inference on model parameters and the impact effects estimates in small samples.  相似文献   
72.
This paper develops Area-wide Leading Inflation CyclE (ALICE) indicators with the aim to provide early signals for turning points in the euro area headline and core inflation cycles. The headline (core) ALICE leads the reference cycle by three (four) months and the lead times extend to five (nine) months based on longer-leading series. Both ALICE indicators signalled turning points in the inflation cycles ex post and also performed well in a simulated real-time exercise. Moreover, in particular the headline ALICE also appeared to be useful for quantitative forecasting of the direction and level of inflation.  相似文献   
73.
Delay propagation is the flight departure delay caused by the arrival delay of pre-segment flight. Chinese airline market has suffered very poor on-time performance (OTP) in recent years. It is, however, unclear whether delay propagation prevails as one major source for such problem. This study first aims to empirically quantify delay propagation in the Chinese airline market. Specifically, we shed light on heterogenous levels of delay propagations across different airports and airlines. Then, the distinct delay propagation patterns in China are also discussed and compared with other developed airline markets (e.g., the US and Europe). Our estimation is based on OTP data for over 12 million Chinese flights covering the 2015–2017 period. Specifically, it is found that 10 min arrival delay of pre-segment flight within 1 hr before the departure lead to an average of 7.49 mins delay propagation for subsequent departure flight. Arrival delay of earlier pre-segments (1–2 and 2–3 hr before the departure) leads to much less delay propagation, due to longer ground buffer. Chinese airlines arrange longer ground and flight buffer than that of the US airlines to prevent the delay propagation from accumulating along the subsequent flights in a day. Thus, unlike the US market, delay propagation is not the major reason for poor OTP in China. In addition, delay propagation is less prevailing at the Chinese hub airport. This is because China has relied on point-to-point network, which does not require sophisticated schedule coordination. And the local passengers at these Chinese hub airports have higher time value such that the Chinese airlines also try to improve OTP at these hub airports to better serve these lucrative but time-sensitive local passengers. Unlike the European LCCs, Spring Airlines, the largest low-cost carrier (LCC) in China, outperforms major full-service carriers (FSCs) in controlling delay propagation. This finding may also apply to other Northeast Asian LCCs sharing common operational characteristics as Spring Airlines. Last, we find that airlines purposely tolerate moderate departure delays of up to 15 min, which is the threshold that defines delays, no matter whether the pre-segment flight arrives late or on-time. The relevant policy and managerial implications are also discussed.  相似文献   
74.
Food product innovations are characterized by high flop rates. In an early development stage, manifold product formulations seem feasible. To determine the most promising product option, market research can help, but is frequently considered too costly and complex. We assess the applicability of the van Westendorp approach, an inexpensive and simple method, for guiding early product design and pricing decisions for novel foods. Findings from a between-subject experiment for meat substitutes consisting of different shares of micro-algae indicate that micro-algae, while a cost driver, has little effect on price preferences. Implications for novel food product design, market research, and retailing are discussed.  相似文献   
75.
This paper analyses the economic and financial repercussions of the 2020 COVID‐19 pandemic. It argues that the pandemic has inflicted serious injuries to the labor force but has not damaged the physical capital stock. Therefore, the resolution policies of this crisis ought to be carefully tailored to supporting structural adjustments to the labor market. The analysis asserts that the impact of the pandemic crisis is exacerbated by the identification gap between the unobserved and the officially reported cases of COVID‐19. The gap increases financial risks, including market‐, credit‐, default‐, and foreign exchange risks.  相似文献   
76.
We investigate the impact of direct payments on agricultural commercialisation in Kosovo. Kosovo is one of the poorest countries in Europe but, with European assistance, provides substantial funds to support agriculture, made up of many small and often semi‐subsistence farms. Thus, the effect of this support is a central policy issue. Identifying the effect of direct payments on market participation faces endogeneity issues arising from the possible simultaneous determination of participation in support programmes and market participation. In order to achieve proper identification of the endogenous direct payments, we use a strategy of targeted identification search that employs several different methodological approaches. We find that direct payments for fruit and vegetables, and those for cereals and oilseeds have a positive effect on market participation. However, we cannot identify any definite effect of livestock payments.  相似文献   
77.
本文基于预期功能安全,采用功能分解方法,总结出部分车辆自动紧急制动(AEB)系统失效和误作用场景,并从中选取典型场景作为测试场景,开展不同车型的实车道路试验,总结出AEB系统的缺陷与隐患分类。希望此类研究能为AEB系统失效和误作用测试标准的制定提供参考。  相似文献   
78.
An Internet nickname is essential in facilitating online interpersonal interactions. It is a pivotal element of interaction that provides other users with an initial impression and affects the decisions and behaviors of users during their online interactions. Although the existing literature has found that nicknames are relevant to users’ psychology and behavior, direct research on the motivation for and the effect of choosing a particular Internet nickname has been very limited. Borrowing from relevant theories on avatars, this paper summarizes the motivations behind Internet nickname choices in terms of three aspects: virtual exploration, social navigation and contextual adaptation. Moreover, from the perspective of collective self-esteem (CSE) and group identification, this research explores the influence mechanism between the motivations underlying Internet nickname choices and users’ online social interactions. A total of 394 samples were obtained from online communities in China to test our research model. We found that virtual exploration, social navigation and contextual adaptation are three motivations for creating Internet nicknames, and they have direct effects on the online social interactions of users. CSE has a full mediating effect between virtual exploration and online social interaction and acts as a mediated variable between social navigation and online social interaction. Group identification fully mediates the relationship between social navigation and online social interaction as well as that between contextual adaptation and online social interaction. The conclusion of this paper provides not only a new perspective for the study of Internet nicknames but also a potentially feasible way to stimulate users’ online social interactions.  相似文献   
79.
Firms are under constant pressure from various governmental and nongovernmental agencies to switch from conventional environmentally polluting products to green product innovations (GPIs). However, the relevant research pertaining to GPI has been published in a diverse set of journals that vary in their scope and readership and, therefore, the scholarly contribution to the topic remains largely fragmented. This study has utilised a systematic literature review approach to examine the literary corpus on GPI to paint a holistic picture of its different aspects. The content and thematic analysis of 85 studies resulted in the extraction of seven key research themes: organisational capabilities, organisational learning, institutional pressures, barriers, structural changes, benefits of GPI, and methodological choices. This study's findings further highlight the various gaps in the GPI literature and raise some research questions that warrant scholarly investigation in the future. Likewise, our study has important implications for practitioners who are likely to benefit from a holistic understanding of the different aspects of GPI. Similarly, policymakers can use this study's findings to introduce policy interventions, especially in countries where GPI adoption is low.  相似文献   
80.
Airport performance differences require a better understanding of the sources of efficiency and competitive advantages. Globalization drives the air transport industry into a more market-orientated business questioning the relationship between managerial decisions and airport performance. Aviation management studies do not consider managerial capabilities and skills since they are intangible exogenous factors that are difficult to assess. In this study, a stochastic frontier analysis is performed accounting for top managers' theoretical knowledge and experience enclosed as exogenous drivers of airports' efficiency. The model analyses 12 Polish airports from 2009 to 2017. The results show a diversity of airports with a different number of passengers as efficient. The top managers' experience, when gained in the same airport, has a positive impact on airports' technical efficiency. Airports having unstable management are more technically inefficient. Independently of the efficiency level, some airports change their management after the national elections, suggesting that managers are chosen by political interest rather than by their specialised knowledge or their prior experience in aviation management. The results suggest that more practical knowledge improve airports’ performance. Airports with a majority of government ownership that are the largest ones increase their efficiency significantly, suggesting that political decisions may be discriminatory in detriment of airports managed by regional and city authorities.  相似文献   
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