Models for count data with endogenous participation

We present several extensions of the Poisson and negative binomial models for count data based on the lognormal model for latent heterogeneity in the conditional means. The lognormal model provides a versatile specification that is more flexible than the familiar log gamma form, and provides a platform for several “two part” extensions that have appeared in the literature, including zero inflation, hurdle and sample selection models. We then extend these received two- part models by allowing for endogeneity of the participation equation. We conclude with a detailed application using the data employed in a recent study of the German health care system.      

The Japanese Taylor rule estimated using censored quantile regressions

This paper conducts quantile regressions and obtains detailed estimates of monetary policy rules in Japan using a sample that includes recent periods of zero interest rates. Taking into account censoring and endogeneity, we compute censored quantile instrumental variable estimators and compare them with estimates from uncensored quantile regressions. The estimation results indicate that not accounting for censoring of interest rates tends to result in downwardly biased estimates. Moreover, our censored quantile regressions lead to relatively flat coefficients of inflation and insignificant coefficients of the output gap over the conditional interest rate distribution, suggesting that monetary policy in Japan may be well described by a linear rule.     

Latent class count models of total visitation demand: <Emphasis Type="Italic">days out hiking in the eastern Alps</Emphasis>

We report preliminary results on the investigation of the hypothesis of the existence of latent classes in the total demand for days out in a vast section of the Italian Eastern Alps. Finite mixing is informed by socioeconomic variables and it is limited to the demand portion of a hurdle model of visitation. Gradually more flexible count models are estimated moving from the Poisson to the Negative Binomial -1 and -2, to the generalized negative binomial. The implications for expected consumers surplus, predicted visitation and choke prices are discussed for a plausible 2 class model where years of experience play an important role in class membership.      

跨层次网络嵌入对发明者二元式创新的影响

发明者的创新活动同时嵌入在知识网络和社会网络中，从多层次网络视角出发，利用华为公司和苹果公司2002-2017年在美专利申请数据，就跨层次网络结构特征对发明者二元式创新的影响进行理论分析，并用负二项回归模型加以实证。结果表明：发明者的跨层凝聚性和跨层连通性均与二元式创新存在倒U型关系;发明者隶属点度加强了跨层凝聚性和跨层连通性与二元式创新之间的倒U型关系。结论弥补了当前单一层面的网络功能机制研究，对指导创新主体构建创新网络具有一定意义。     

Effects of policy instruments on farm investments and production decisions in the Spanish COP sector

Our article assesses the impacts regarding on-farm investment and production decisions resulting from the Partially Decoupled (PD) payment scheme implemented during the 1990s and first half of the 2000s within the framework of the Common Agricultural Policy (CAP). The Spanish Cereal, Oilseed and Protein (COP) sector is taken as a case study regarding this effect due to its economic and political relevance in Spain. The empirical analysis is applied to farm-level data from 2000 to 2004 using the Farm Accountancy Data Network (FADN). We use a reduced-form application of the dual model of investment under uncertainty and estimate a system of censored and uncensored equations. PD payments are found to increase short-run production and generate a statically significant increase in the investment in farm assets. Results also show the importance of assessing the effects of PD payments in a dynamic framework as applied in this article.     

An alternative bivariate zero-inflated negative binomial regression model using a copula

We propose an alternative bivariate zero-inflated negative binomial (BZINB) regression model based on a copula. The empirical result shows that the proposed model performs better than the existing BZINB models in terms of the maximum log-likelihood and the AIC.     

技术相似关系对技术创新绩效的影响

不同阈值水平的技术相似关系可以在一定程度上反映产业内的技术竞争情况,由此构建了全球研发领先的88家通信及技术设备制造类企业的技术相似关系网络和合作关系网络,利用负二项回归模型分析了技术相似关系对创新绩效的作用。分析结果表明：当技术相似度阈值在0.3和0.5水平时,技术相似关系负向影响创新绩效,合作直接关系部分或完全中介调节两者关系。     

The relationship between R&D,investment and patents: a panel data analysis

This paper estimates the effect of research and investment activities on patents across countries, industries and over time, using Poisson and negative binomial distribution models. The first result of the paper is the recognition of the importance of investment activities in contributing to technical change. The positive role of research expenditures is also confirmed but its elasticity is found to be lower than in previous studies. Important differences across sectors emerge: research expenditures are found to be more effective in generating patents in science based industries, while investment is particularly significant in supplier dominated and production intensive industries. Finally, in most sectors, the estimated R&D and investment coefficients lie outside the confidence intervals calculated around the pooled coefficients.     

Determinants of youth not in education,employment or training: Evidence from Sri Lanka

The presence of a large proportion of youth neither in education, employment, or training (NEET) signals problems in a country’s education and labor market systems, and has wide‐ranging negative consequences, extending beyond the individual to the economy and society. Using Sri Lankan Labour Force Survey data for the year 2016 and binomial and multinomial logistic regression models, in this paper we provide the first estimates of NEET‐related risk factors in Sri Lanka. Key risk factors of becoming NEET include being female, being of ethnic and religious minorities, belonging to the older 20 to 24 age group, having very low or very high levels of education, being illiterate in English, belonging to a low‐income household or one headed by a male, having young children, and living in more remote areas. Our findings hold several important policy implications for reducing the NEET rate in Sri Lanka and engaging more youth in education and in the labor force.     

Alternative Models of Recreational Off-Highway Vehicle Site Demand

A controversial recreation activity is off-highway vehicle use. Off-highway vehicle use is controversial because it is incompatible with most other activities and is extremely hard on natural eco-systems. This study estimates utility theoretic incomplete demand systems for four off-highway vehicle sites. Since two sets of restrictions are equally consistent with utility theory both are imposed and the best fitting restrictions are identified using Voung’s non-nested testing scheme. The demand system is modeled using both Poisson and negative binomial II distributions. Data are provided by a survey conducted at four recreational off-highway vehicle (OHV) sites in western North Carolina.     

科技项目资助对论文产出绩效的作用效率测度研究

以人工智能领域论文和学者为研究对象,探讨科技项目资助对论文产出绩效的作用效率。运用负二项回归分析不同国家、领域资助种类、强度对论文引用和载文期刊水平的影响,结果发现,各项资助指标均可提升论文质量,但在不同地域和研究方向上的作用效果有所差异。运用倾向得分分层和线性回归,从发文、被引量和h指数角度测度资助对学者产出绩效提升的有效性,结果发现,资助能够显著提升学者产出力和影响力。通过Tobit回归测度资助项目数量和金额对不同年龄群体学者发文、被引量与变化率等指标的影响,结果发现,资助项目数量增加可整体提升学者产出绩效,资助金额增加更能扩大产出力和影响力的动态提升幅度。据此,提出资助改进策略和评审机制优化等相关建议。     

A Poisson ridge regression estimator

The standard statistical method for analyzing count data is the Poisson regression model, which is usually estimated using maximum likelihood (ML) method. The ML method is very sensitive to multicollinearity. Therefore, we present a new Poisson ridge regression estimator (PRR) as a remedy to the problem of instability of the traditional ML method. To investigate the performance of the PRR and the traditional ML approaches for estimating the parameters of the Poisson regression model, we calculate the mean squared error (MSE) using Monte Carlo simulations. The result from the simulation study shows that the PRR method outperforms the traditional ML estimator in all of the different situations evaluated in this paper.     

外部联系对研发人员探索式创新的影响——内部直接联系、外部合作网络多样性的调节效应

企业利用外部合作网络获取丰富的异质性资源，已成为促进探索式创新的重要途径，而研发人员作为企业创新活动主体，其合作网络的外部联系会影响个体探索式创新，进而影响企业整体探索式创新绩效。基于社会网络理论，在考虑内部直接联系和外部合作网络多样性调节效应的基础上，建立研发人员外部联系对探索式创新影响的概念模型，并提出研究假设。以我国电子信息制造业代表性企业华为公司与中兴公司为例，采用国家专利局授权的发明专利数据，利用负二项回归模型进行实证检验。研究结果表明：研发人员外部联系与其探索式创新呈显著倒U型关系；内部直接联系、外部合作网络成员多样性、外部合作网络知识多样性对二者的倒U型关系具有显著负向调节作用。     

EXTERNAL HEALTH COSTS OF A STEEL MILL

Intermittent operation of a steel mill in a mountain valley in central Utah provides a unique opportunity to measure the external health costs of air pollution. A nearby valley provides a control. This paper analyzes data on hospital admissions and daily deaths for the two valleys, using negative binomial regression models of daily hospital admissions and deaths. Hospital admissions for respiratory diseases increase significantly when the mill is in operation. Mortality also increases during mill operation. Estimated excess hospitalization costs are about 2 million dollars per year, and the increased cost of mortality exceeds 40 million dollars per year.     

Optimal income taxation in models with endogenous fertility

This paper studies the efficient taxation of factor income in infinite-lived models with elastic fertility choices. Two models are considered, one with physical capital only, and one with physical and human capital. In the model with physical capital only, capital income should be subsidized, while labor income taxed. In the model with two types of capital, instead, Ramsey optimality prescribes that the tax on physical capital is zero (negative), if effective labor is constant (decreasing) returns to scale in human capital and market goods, while the tax on human capital is negative and the tax on effective labor positive. Our findings depart from those obtained in immortal models with an endogenous labor supply and constant population growth, because physical and human capital affect the demand for fertility.     

外部联系对研发人员探索式创新的影响——内部直接联系、外部合作网络多样性的调节效应

企业利用外部合作网络获取丰富的异质性资源，已成为促进探索式创新的重要途径，而研发人员作为企业创新活动主体，其合作网络的外部联系会影响个体探索式创新，进而影响企业整体探索式创新绩效。基于社会网络理论，在考虑内部直接联系和外部合作网络多样性调节效应的基础上，建立研发人员外部联系对探索式创新影响的概念模型，并提出研究假设。以我国电子信息制造业代表性企业华为公司与中兴公司为例，采用国家专利局授权的发明专利数据，利用负二项回归模型进行实证检验。研究结果表明：研发人员外部联系与其探索式创新呈显著倒U型关系；内部直接联系、外部合作网络成员多样性、外部合作网络知识多样性对二者的倒U型关系具有显著负向调节作用。     

Do High Oil Prices Matter? Evidence on the Mobility Behavior of German Households

Focusing on travel survey data from Germany, this paper investigates the determinants of automobile travel, with the specific aim of quantifying the effects of fuel prices and fuel economy. The analysis is predicated on the notion that car mileage is a two-stage decision process, comprising the discrete choice of whether to own a car and the continuous choice of distance traveled. To capture this process, we employ censored regression models consisting of Probit and OLS estimators, which allows us to gauge the extent to which sample selectivity may bias the results. Our elasticity estimates indicate a significant positive association between increased fuel economy and increased driving, and a significantly negative fuel-price elasticity, which ranges between − 35% and − 41%. Taken together, these results suggest that fuel taxes are likely to be a more effective policy measure in reducing emissions than fuel-efficiency standards.      

Sectoral determinants of foreign affiliate sales employing European data

We test theories on sectoral determinants of foreign affiliate sales employing European foreign affiliate sales statistics (FATS). On the one hand, we test hypotheses that foreign affiliate sales are less likely in sectors with complex tasks and more likely in sectors where communication with customers is important. On the other hand, we test the hypothesis that the force of gravity is stronger in more complex sectors. Employing Poisson and negative binomial estimators, we find support for the first hypotheses and contradict the second hypothesis. We show that the interaction effect between distance and complexity changes sign from negative to positive when complexity is included as a separate regressor. We propose an explanation to reconcile our findings with the basic assertion in the second hypothesis that the force of gravity is stronger in more complex sectors, based on a composition effect between horizontal and vertical affiliate sales.     

Public acceptance of and heterogeneity in behavioral beach trip responses to offshore wind farm development in Catalonia (Spain)

A combined travel cost – contingent behaviour survey of residents and tourists in Catalonia is conducted on-site to examine the effects on beach recreational demand of developing an offshore wind farm (OWF) project. The survey considers four potential OWF scenarios with different degrees of visual impact. We allow for heterogeneity in trip preferences among individuals and control for on-site sampling through the use of a random parameters negative binomial (RPNB) model and a Multivariate Poisson log-normal (MPLN) model, respectively. The welfare measures derived from the RPNB model relate to the current beach users only, whereas those from the MPLN model refer to the general population of residents and tourists in Catalonia. The results show the importance of the specific place of location of the OWF project and how the installation of wind turbines would significantly decrease the demand for trips, depending on their degree of visual impacts, leading to a substantial welfare loss. However, the results also show that the project mainly would cause a displacement of trips to other beaches within Catalonia rather than outside Catalonia and that the welfare per trip measures generated by the RPNB and MPLN models substantially differ. Policy implications of these findings are discussed.