收入差距、有效需求与自主创新

文章利用中国地区层面的面板数据,实证检验了收入差距与自主创新之间的关系。研究发现,收入差距与中国自主创新呈倒"U"形关系,收入差距既可以通过扩大创新产品的需求规模促进国家或地区的技术创新,又可以通过抑制消费结构升级最终阻碍国家或地区技术创新能力的提升;收入差距对技术创新的影响存在显著的区域差异性,在东部和中部地区其影响显著为正,而在西部地区其影响为负但不显著;当前,我国大部分地区的城乡收入比均处于倒"U"形曲线的上升阶段,对这些地区而言,适当的收入差距促进了其自主创新能力的提升。     

微气泡曝气中微气泡收缩特性研究

微气泡曝气是一种新的气泡曝气方式,气泡特性对微气泡曝气性能具有显著影响。采用气-水旋流微气泡发生装置,考察了微气泡曝气中气泡尺寸和微气泡收缩特性及其影响因素。结果表明,微气泡发生装置在清水中产生的微气泡平均直径为55.85μm,标准偏差为30.03μm;40～50μm直径范围内的微气泡所占的体积分率最大,表面活性剂SDS会降低微气泡的平均直径。微气泡具有加速收缩消失的行为特性,微气泡初始直径与收缩时间之间存在显著的正相关关系,静态条件下相同初始直径的微气泡收缩过程存在明显差异。表面活性剂SDS存在时,微气泡的收缩时间显著延长。微气泡的收缩时间与传质区域面积具有负相关关系,表明微环境影响微气泡收缩过程。     

地方政府规模影响因素实证分析

本文从公共服务需求角度出发,运用中国31省面板数据检验了地方政府规模的影响因素。研究发现：（1）我国地方政府规模发展趋势符合瓦格纳法则,同时满足对外经济的效率假说和补偿假说;（2）民族多元化对地方政府规模有显著的正向影响;（3）上期政府收入对政府支出有很大的正向影响,说明二者之间互为因果关系。     

From passenger growth to aircraft movements

Airlines are able to deal with passenger growth by either increasing the frequency or the aircraft size, which may entail different numbers of aircraft movements. Forecasting the latter is necessary for evaluating technologies, approaching future emissions or anticipating capacity constraints. Purpose of this paper is to forecast a typical fleet mix and the growth of aircraft movements on flight segments worldwide based on an assumed passenger growth. The methodology is implemented in a model called Forecast of Aircraft Movements. Basic approach is the assignment of each flight segment worldwide to a distance, passenger number and aircraft category. For each combination of distance and passenger numbers a typical fleet mix is defined. The forecasted worldwide growth of passenger demand and the empirically determined fleet mix is applied to all segments in order to derive a future scenario. Assuming a certain seat load factor, the frequency growth can be deduced from the aircraft movements generated for all segments. The paper includes a forecast for aircraft movements in a future scenario based on real schedule and passenger data and gives a detailed overview of the methodology and results considering airlines' behaviour.     

Economies of traffic density and scale in the integrated air cargo industry: The cost structures of FedEx Express and UPS Airlines

This paper examines the cost structures of the leading integrated air cargo carriers, FedEx Express and UPS Airlines. A total cost model is estimated for the two carriers using quarterly data on domestic operations and costs over a nine-year period (2003–2011). The estimated model indicates that the integrated industry exhibits increasing returns to traffic density and constant returns to scale. Accounting for carrier-specific differences in cost structure and network size, FedEx Express is found to be more cost-efficient than UPS Airlines. Looking at the carriers individually, UPS Airlines exhibits substantial economies of traffic density and constant returns to scale while FedEx Express' cost structure is characterized by weak economies of density and constant returns to scale. The combined effect of returns to density and returns to scale on the cost structures of integrated carriers is captured by economies of size. Both FedEx Express and UPS Airlines exhibit economies of size, indicating that carriers in the integrated industry can be more cost efficient by making appropriate adjustments to their network size as their output grows. Moreover, the relative cost-efficiencies of the carriers are reversed when their network-size differences are not controlled.     

Growth-focused or profit-focused firms: Transitions toward profitable growth

Profitable growth is the most desirable state tourism and hospitality firm managers can hope to achieve. In reality, however, it is not easy for a tourism and hospitality firm to consistently grow and accumulate profits. In order to achieve profitable growth, some firms focus on sales growth while victimizing profits, while others concentrate on profits and hold off on growth. To better understand these strategies, this study investigated the growth state, profit state and transitions of restaurant firms. The findings of this study supported that profit-focused firms are more likely to achieve profitable growth than growth-focused firms. In addition, growth-focused firms with low liquidity had a higher likelihood of transitioning to a state of low growth and low profit in the short-term, and this liquidity effect was more serious for small firms in terms of long-term performance. Further, when profit-focused firms had few growth opportunities, large free cash flows increased the likelihood of transitioning to a state of low growth and low profit in the short-term. More detailed results are provided in this paper.     

Unobserved firm heterogeneity and the size-exports nexus: Evidence from German panel data

This paper starts from the stylized fact that firm size and exporting tends to be positively related. Using large sets of establishment panel data for three different industries from official statistics, evidence is presented that the familiar picture of an export/sales ratio that increases (at a decreasing rate) with firm size vanishes if unobserved firm heterogeneity is controlled for in a fixed-effects fractional logit regression model. This finding is well in line with the fact that many small firms are “hidden export champions.” JEL no. F10, D21, L60     

Analysis of Korean millennials’ travel expenditure patterns: an almost ideal demand system approach

ABSTRACT

Generational cohorts can differ in their consumption patterns and preferred travel behavior. As the millennial generation represents an important economic force and influences new consumption trends, this study utilizes nationwide data and almost ideal demand system (AIDS) approach to examine expenditure patterns of Korean travelers during holidays. In this process, the joint effects of travel-related characteristics are also examined. The results of the AIDS estimation on data from 871 domestic travelers reveal significantly different travel expenditure patterns for cohorts. The findings contribute to furthering the understanding of how different generational cohorts allocate their travel budgets to respective travel expenditure categories.     

Modelling international tourism and country risk spillovers for Cyprus and Malta

Small Island Tourism Economies (SITEs) are developing sovereign countries that rely on tourism as a source of exports, and need a consistent inflow of foreign investment in order to facilitate economic growth. Access to international capital markets helps SITEs smooth out their consumption over time, while absorbing adverse domestic production shocks. This paper provides a comparison of tourism growth, country risk returns and their associated volatilities (or uncertainty) for 2 SITEs, namely Cyprus and Malta. Monthly data are available for both international tourist arrivals and composite country risk ratings compiled by the International Country Risk Guide (ICRG) for the period May 1986 to May 2002. The time-varying conditional variances of tourism growth and country risk returns for the 2 SITEs are analysed using multivariate models of conditional volatility. Empirical results show that Cyprus and Malta are complementary destinations for international tourists. Changes to tourism patterns in Cyprus lead to changes to tourism patterns in Malta. Hence, tour operators and national tourism promotion authorities in Cyprus and Malta should collaborate closely in marketing and promoting joint tourism products. Moreover, foreign entities interested in investing in the tourism sectors of Cyprus and Malta should consider investment projects that span a long period of time. The performance of the tourism sector and the associated composite risk are independent of each other for the two countries. However, there is a direct relationship between the tourism sectors of Cyprus and Malta and their respective country risk settings.     

Agricultural productivity growth in Brazil: Large and small farms excel

The long-standing debate on the relationship between farm size and productivity has been generally limited by the range of farm sizes evaluated and the definition of productivity. In this paper we use data from three Brazilian agricultural censuses to address these issues. In particular, we introduce a wider distribution of farm sizes than presently available from the literature and we employ total factor productivity (TFP) as our performance measure. In doing so, we test which farm size class had the highest TFP levels in 1985 and 2006, how factor productivity growth varied within and across farm size classes between those years, and which policy or factor had the greatest productivity enhancing effect. When examining TFP growth, we move beyond the common decomposition into technical and efficiency changes by identifying the complete distribution of farm productivity performances. We find that by 2006 a U-shaped distribution of productivity over farm sizes had emerged. Considerable 1985–2006 TFP growth differences are prevalent; positive rates for the majority accompany stagnant or negative rates for some. Public education investments were associated with faster productivity growth regardless of farm size, while technical assistance’s positive effect and credit’s negative effect were associated with larger farm sizes. The role of specialization varied by size.