The Dynamics of REIT Pricing Efficiency

We study the dynamics of pricing efficiency in the equity REIT market from 1993 to 2014. We measure pricing efficiency at the firm level using variance ratios calculated from quote midpoints in the TAQ database. We find four main results. First, on average, the market is efficient, with variance ratios close to one. However, in any given year, there is considerable cross‐sectional variation in variance ratios, suggesting at least some firms are priced inefficiently. Second, higher institutional ownership by active institutional investors is related to better pricing efficiency, while passive ownership does not reduce pricing efficiency. Third, REITs that are included in the S&P 500 and S&P 400 are priced more efficiently than other REITs. For the S&P 500 firms, we find evidence that this was purely driven by sample selection, while for S&P 400 firms, we find evidence that it is inclusion in the index that drives efficiency. Finally, we find evidence that firm investment, analyst coverage and debt capital raising activity can influence pricing efficiency.     

THE EFFECT OF AUCTION FORMAT ON EFFICIENCY AND REVENUE IN DIVISIBLE GOODS AUCTIONS: A TEST USING KOREAN TREASURY AUCTIONS*

This paper measures the efficiency and revenue properties of the two most popular formats for divisible goods auctions: the uniform‐price and discriminatory auction. We analyze bids into the Korean Treasury auctions which have used both formats. We find that the discriminatory auction yields statistically higher revenue. Unlike previous work that uses data from only one format, we are able to compare the efficiency properties of the two formats. We find that the discriminatory auction better allocates treasury bills to the highest value financial institutions. However, the differences in revenue and efficiency are not large because the auctions are very competitive.     

基于DEA的工业行业科技投入有效性评价——基于山东省工业行业的研究

以山东省规模以上工业企业为研究对象,在建立工业企业科技投入——产出效率评价指标体系的基础上,运用DEA方法对各工业行业的科技投入产出效率进行综合测度。根据DEA评价结果得出,山东省大多数工业行业的科技投入产出效率较低,各工业行业之间差距较大,发展很不平衡,而且总体产出水平也不高,科技投入的力度和结构有待改善。     

Analyzing the impact of user-generated content on B2B Firms' stock performance: Big data analysis with machine learning methods

Marketing scholars are interested in the big data of user-generated content (UGC) from social media platforms. However, the majority of current UGC studies have been conducted in the business-to-consumer (B2C) context. To fill the knowledge gap in business-to-business (B2B) research, we investigate whether UGC has differential impacts on stock performance for B2B and B2C firms by using big data. We collect a large dataset of 84 million tweets from 20.3 million Twitter accounts and 8 years of stock data for 407 companies from the S&P500 index. The results from machine learning methods are transformed into a monthly panel data. We conduct fixed effects model on the panel data. We find that UGC has a significant impact on firms' stock performance and that its impact on stock performance is much stronger among B2C firms than among B2B firms. While consumers' positive sentiment does not play a significant role in stock performance, consumers' negative sentiment and WOM significantly impact stock prices.     

An extension to the classical mean–variance portfolio optimization model

Abstract

The purpose of this study is to find a portfolio that maximizes the risk-adjusted returns subject to constraints frequently faced during portfolio management by extending the classical Markowitz mean–variance portfolio optimization model. We propose a new two-step heuristic approach, GRASP & SOLVER, that evaluates the desirability of an asset by combining several properties about it into a single parameter. Using a real-life data set, we conduct a simulation study to compare our solution to a benchmark (S&P 500 index). We find that our method generates solutions satisfying nearly all of the constraints within reasonable computational time (under an hour), at the expense of a 13% reduction in the annual return of the portfolio, highlighting the effect of introducing these practice-based constraints.     

Do Different Measures of Hospital Competition Matter in Empirical Investigations of Hospital Behavior

Considerable controversy exists about the appropriate way hospital competition should be measured and whether findings are accurate if certain methods are employed. Data from the Healthcare Cost and Utilization Project (HCUP), the American Hospital Association (AHA), and other supplemental data sources are used to create and evaluate hospital competition measures. Correlation coefficients of these measures are assessed. Moreover, each measure is independently included as an explanatory variable in otherwise identical hospital cost function regressions. Their corresponding parameter estimates are then compared. Most measures are highly correlated. Inferences about the effect of competition on hospital cost remain the same when alternative hospital competition measures are employed. We caution researchers against using this finding to arbitrarily select a competition measure when the magnitude of the estimates is important.JEL Classifications: I11, L19.This paper does not represent the policy of either the Agency for Healthcare Research and Quality (AHRQ) or the U.S. Department of Health and Human Services (DHHS). The views expressed herein are those of the authors and no official endorsement by AHRQ or DHHS is intended or should be inferred.     

环境规制绩效及其影响因素的实证分析

本文选取1999～2011年中国30个省份的相关面板数据,首先运用DEA模型对中国环境规制的绩效进行了测算,继而运用面板回归模型实证分析了规制绩效的影响因素。研究结论表明：2000～2011年间,全国样本的环境规制绩效虽有波动,但总体呈逐年增长趋势,特别是2006年以后,增长趋势趋于稳定;就区域和省际层面而言,则表现出较大的差异性。面板回归分析的结果表明,影响环境规制绩效的因素较多,其中经济发展水平和外商直接投资成为促进环境规制绩效提高的积极因素,而环保力度和受教育水平则不利于规制绩效的提高。     

THE IDENTIFICATION OF TARGET FIRMS AND FUNCTIONAL AREAS FOR STRATEGIC BENCHMARKING

In recent years there has been an increased emphasis on quality, Total Quality Management (TQM), and re-engineering. The practice of benchmarking is inherent to the success of any of these. Despite its obvious strategic implications, benchmarking has received little theoretical or analytical attention in the literature. Moreover, studies show that many firms are unsure about how to implement the benchmarking process. A critical aspect of benchmarking is the identification of who to benchmark against and what functional areas to benchmark. In this paper we show that Data Envelopment Analysis (DEA) can provide a structured methodology which, when used in conjunction with expert/managerial insight, can be a useful toot for providing necessary analytic support for the managerial practice of benchmarking. DEA uses multiple input and multiple output measures to assess efficiency. In this paper we first use DEA analysis to identify a subset of efficient firms which could be targeted for benchmarking. In a second stage, a constrained least absolute value (goal programming) method is used to ascertain input elasticities for the designated efficient firms in order to pinpoint important specific areas for benchmarking comparisons. We use macro-level data from the computer industry to illustrate this application of DEA and constrained least absolute value regression to benchmarking.     

ROBUSTNESS OF PRODUCTIVITY ESTIMATES*

Researchers interested in estimating productivity can choose from an array of methodologies, each with its strengths and weaknesses. We compare the robustness of five widely used techniques, two non‐parametric and three parametric: in order, (a) index numbers, (b) data envelopment analysis (DEA), (c) stochastic frontiers, (d) instrumental variables (GMM) and (e) semiparametric estimation. Using simulated samples of firms, we analyze the sensitivity of alternative methods to the way randomness is introduced in the data generating process. Three experiments are considered, introducing randomness via factor price heterogeneity, measurement error and differences in production technology respectively. When measurement error is small, index numbers are excellent for estimating productivity growth and are among the best for estimating productivity levels. DEA excels when technology is heterogeneous and returns to scale are not constant. When measurement or optimization errors are nonnegligible, parametric approaches are preferred. Ranked by the persistence of the productivity differentials between firms (in decreasing order), one should prefer the stochastic frontiers, GMM, or semiparametric estimation methods. The practical relevance of each experiment for applied researchers is discussed explicitly.     

Productivity Change,Technical Progress,and Efficiency Improvement in Telecommunications

Implementation of incentive regulation intelecommunications requires the accurate measurementof the change in productivity. An approach isintroduced that not only provides a measure of thechange in productivity but also allows for adecomposition into two mutually exclusive andexhaustive components – changes in technicalefficiency over time and shifts in technology overtime. Using annual data on four output measures andsix input measures for the period 1988 to 1998 fornineteen individual local exchange carriers, theresults indicate that productivity increased by about5.0 percent per year. This growth is due primarily toinnovation rather than improvements in efficiency. Ofthe nineteen LECs in the sample, thirteen wereoperating efficiently throughout the entire 1988–1998period. Of the remaining six, two showed a slightimprovement in efficiency while the efficiency of fourdeclined. In the aggregate, however, there wasvirtually no change in efficiency. Finally, acomparison is made between two methods of estimatingthe change in productivity. The conventional growthaccounting approach yields a lower estimate of therate of change in productivity than does the Malmquistindex approach. The difference between theseestimates is interpreted as the lower bound of thebias associated with the conventional growthaccounting approach to measuring the growth inproductivity.     

Sickness Absence and Works Councils: Evidence from German Individual and Linked Employer–Employee Data

Using both household and linked employer–employee data for Germany, we assess the effects of nonunion representation in the form of works councils on (1) individual sickness absence rates and (2) a subjective measure of personnel problems due to sickness absence as perceived by a firm's management. We find that the existence of a works council is positively correlated with the incidence and the annual duration of absence. Further, personnel problems due to absence are more likely to occur in plants with a works council.     

The Impact of Competition on the Efficiency of Public Enterprise: The Case of Korea Telecom

The notion of total productivity can be employed in evaluating the performance of monopolistic public enterprises in a transitional period. This study comparatively analyzes the efficiency change of Korea Telecom (KT) once the biggest telecommunications service provider in Korea but now facing both domestic and foreign competition. Dichotomizing the reference period into before-competition and after-competition and using Data Envelopment Analysis (DEA), we measure the technical efficiency, the allocative efficiency and the overall efficiency and highlight the differences between two periods. It is observed that the overall efficiency has been significantly improved mainly due to the enhancement of the allocative efficiency but the technical efficiency has been slightly improved. The major cause of insignificant improvement of technical efficiency is due to hothouse competition and excessive regulation on management of KT. Monopolistic firms in transition can respond to the external competition by reducing input cost and excessive capital. There may exist a considerable time lag, however, in achieving the improvement of technical efficiency.     

Analyzing the Welfare Impacts of Full‐line Forcing Contracts

Theoretical investigations have examined both anti‐competitive and efficiency‐inducing rationales for vertical bundling, making empirical evidence important to understanding its welfare implications. We use an extensive dataset on full‐line forcing contracts between movie distributors and video retailers to empirically measure the impact of vertical bundling on welfare. We identify and measure three primary effects of full‐line forcing contracts: market coverage, leverage and efficiency. We find that bundling increases market coverage and efficiency, but has little impact on one distributor's gaining leverage over another. As a result, we estimate that full‐line forcing contracts increased consumer and producer surplus in this application.     

基于网络DEA的科技创新型企业投资效率评价分析

企业投资效率是影响企业价值的关键因素。本文在划分投资转化过程子阶段的基础上构建投资效率评价模型及指标体系,运用二阶段网络DEA方法测算我国创业板科技创新型上市公司2012～2014年投资效率值及非效率投资的改进程度。实证结果表明,科技创新型上市公司利润产生子阶段投资效率较低,并且研发支出、无形资产以及长期投资三方面的投资冗余现象明显,但是多数上市公司两个阶段的投资效率随着时间的推移逐渐趋向双重高效。     

Conflict,food price shocks,and food insecurity: The experience of Afghan households

Using nationally-representative household survey data and confidential geo-coded data on violent incidents, we examine the relationship between conflict and food insecurity in Afghanistan. Spatial mappings of the raw data reveal large variations in levels of food insecurity and conflict across the country; surprisingly, high conflict provinces are not the most food insecure. Using a simple bivariate regression model of conflict (violent incidents and persons killed or injured) on food security (calorie intake and the real value of food consumed), we find mixed associations. But once we move to a multivariate framework, accounting for household characteristics and key commodity prices, we find robust evidence that in Afghanistan levels of conflict and food security are negatively correlated. We also find that households in provinces with higher levels of conflict experience muted declines in food security due to staple food price increases relative tohouseholds in provinces with lower levels of conflict, perhaps because the former are more disconnected from markets. Gaining a better understanding of linkages between conflict and food insecurity and knowing their spatial distributions can serve to inform policymakers interested in targeting scarce resources to vulnerable populations, for example, through the placement of strategic grain reserves or targeted food assistance programs.     

Regulatory Risk and Market Reactions — Empirical Evidence from Germany

In this article we measure the effects of events on risk and return and analyze the persistence of the influencing variables on German energy companies. Therefore, we refer to event-study methods by means of the Capital Asset Pricing Model, GARCH-Modeling and Kalman filters. We find that the discussed events do not affect all companies in an equal manner. Moreover, we show that the impact on risk and returns is not persistent and does not lead to an increase in the overall systematic risk for the considered utility operators in Germany.     

Flawed Competition Policies: Designing ‘Markets’ with Biased Costs and Efficiency Benchmarks

Rather than the endogenous, tournament-type regulation based on mean costs proposed by Shleifer almost twenty years ago, regulators have opted for market designs based on exogenously determined efficiency comparisons reflected in fixed productivity adjustments. These productivity assessments are based only on estimates of technical efficiency improvements derived from estimated production frontiers. Utilities’ prices and potential profits are driven by this externally determined market. This paper examines the impacts on utility efficiency rankings from variations in peer group frontier regulation in Europe and Australia as well as in its use in the U.S. Despite the potential for distortions caused by long periods with non-market prices, these regulatory applications measure only technical efficiency, leaving moot the assessment of optimal input selection. We examine both technical and allocative efficiency variations among firms from the different cost specifications employed by regulators involving output, factor inputs, and costs. How are rankings impacted when only subsets of total costs (e.g., O&;M, not capital or system losses) are used to gauge efficiency? Does the use of partial measures of capital relying on physical specifications impact efficiency rankings? Are rankings affected when comparisons are made independently one input at a time? Is the efficiency frontier stable? Finally, we compare alternative yardstick measures to a simple ranking on relative (total) cost per unit.     

基于DEA的我国钢铁企业节能减排潜力研究

本文基于数据包络分析(DEA)的基础理论和方法,从不期望产出的角度出发,将钢铁产业污染物排放作为一种非期望输入引入到数据包络分析模型中,并将该模型应用于我国钢铁产业生态效率评价及节能减排潜力的研究。研究结论表明,我国各钢铁企业生态效率总体上不高,但呈现出逐渐增强的趋势;通过进一步的钢铁企业效率改进分析得知,我国钢铁企业还存在着较严重的投入拥挤和产出不足现象,仅从钢铁企业的47家样本来看,我国钢铁企业有着巨大的节能减排潜力。     

Chief strategy officers: Contingency analysis of their presence in top management teams

Drawing upon contingency theory, we analyze the antecedents and performance consequences of chief strategy officer (CSO) presence in top management teams (TMTs). We argue that strategic and structural complexity affects the decision to have a CSO in the TMT and its effect on firm performance. The results of a sample of S&P 500 firms over a five‐year period reveal that diversification, acquisition activity, and TMT role interdependence are positively associated with CSO presence. However, we also find that the structural choice to have a CSO in the TMT does not significantly affect a firm's financial performance. This first systematic analysis of CSO presence informs research on CSOs and contributes to the emerging literature on TMT structure. Copyright © 2013 John Wiley & Sons, Ltd.     

Content validation of a measure of R&D effectiveness

The overall purpose of this paper is to analyse the content validity of a tool for measuring research and development (R&D) effectiveness in industry using an approach known as scale or construct validation.
Since a large number of indicators is needed in order to measure this concept, and it is often difficult to find qualitative measures that would provide more information than quantitative measures or purely numerical magnitudes, we have constructed a scale that enables us to create a multiindicator to measure R&D inputs, processes, outputs and results. This multiindicator also enables us to group together all the relevant data obtained from the R&D management literature, which we then validate by consulting the opinion of experts from two firms that are very active in R&D and we have consulted two more nationally recognized Spanish researchers on R&D.