WHY AGNOSTIC SIGN RESTRICTIONS ARE NOT ENOUGH: UNDERSTANDING THE DYNAMICS OF OIL MARKET VAR MODELS

Sign restrictions on the responses generated by structural vector autoregressive models have been proposed as an alternative approach to the use of exclusion restrictions on the impact multiplier matrix. In recent years such models have been increasingly used to identify demand and supply shocks in the market for crude oil. We demonstrate that sign restrictions alone are insufficient to infer the responses of the real price of oil to such shocks. Moreover, the conventional assumption that all admissible models are equally likely is routinely violated in oil market models, calling into question the use of posterior median responses to characterize the responses to structural shocks. When combining sign restrictions with additional empirically plausible bounds on the magnitude of the short‐run oil supply elasticity and on the impact response of real activity, however, it is possible to reduce the set of admissible model solutions to a small number of qualitatively similar estimates. The resulting model estimates are broadly consistent with earlier results regarding the relative importance of demand and supply shocks for the real price of oil based on structural vector autoregressive (VAR) models identified by exclusion restrictions, but imply very different dynamics from the posterior median responses in VAR models based on sign restrictions only.     

UNINSURED COUNTERCYCLICAL RISK: AN AGGREGATION RESULT AND APPLICATION TO OPTIMAL MONETARY POLICY

We consider an incomplete markets economy with capital accumulation and endogenous labor supply. Individuals face countercyclical idiosyncratic labor and asset risk. We derive conditions under which the aggregate allocations and price system can be found by solving a representative agent problem. This result is applied to analyze the properties of an optimal monetary policy in a New Keynesian economy with uninsured countercyclical individual risk. The optimal monetary policy that emerges from our incomplete markets economy is the same as the optimal monetary policy in a representative agent model with preference shocks. When price rigidity is the only friction the optimal monetary policy calls for stabilizing the inflation rate at zero.     

串口通讯Linux和Windows下的实现与比较

结合实际工作中串口通讯的经验,讨论了串口通讯在Linux和Windows下的具体实现,并从开发环境、实现方法、调试工具多个方面比较了二者的不同,可为串口通讯的实际应用提供参考.     

利用VPN技术实现基于远程的教学、教务管理信息系统

本文介绍了远程教育中的教学、教务信息化中存在的问题,VPN技术的工作原理,基于WINDOWS 2000的VPN技术在远程教学、教务管理信息系统中的应用,及VPN技术在远程教学、教务管理信息系统中的实现方法.     

PAYROLL TAXES,SOCIAL INSURANCE,AND BUSINESS CYCLES

Payroll taxes represent a major distortionary influence of governments on labor markets. This paper examines the role of time‐varying payroll taxes and the social safety net for cyclical fluctuations in a nonmonetary economy with labor market frictions and unemployment insurance, when the latter is only imperfectly related to search effort. A balanced social insurance budget induces countercyclical payroll taxation, renders gross wages more rigid over the cycle and strengthens the model's endogenous propagation mechanism. For conventional calibrations, the model generates a negatively sloped Beveridge curve and countercyclical unemployment as well as substantial volatility and persistence of vacancies and unemployment.     

Ownership structure and board composition in a high ownership concentration context

Few articles have addressed the relation between the ownership structure and the composition of the boards. The results of the analysis performed on a sample of Spanish listed companies for the period 2004–2011, show that in markets where corporate ownership is highly concentrated, it is necessary to devote special attention to blockholders and to differentiate the figure of the independent directors from the group of outsiders. The results confirm a negative and decreasing relation between blockholders and the percentage of independents while insiders’ ownership is only significant if one looks at the percentage of outsiders as a whole, in which case it shows a U-shaped quadratic relation.     

Connecting external knowledge usage and firm performance: An empirical analysis

Prior research suggests that firms create breakthrough innovations by using external knowledge, but it also underscores the difficulties firms face in acquiring and applying external knowledge. In this paper, we combine these insights to examine the conditions under which external knowledge usage will either enhance or erode firm performance. In particular, we argue that high external knowledge usage has a negative effect on performance when firms enter multiple new product markets, but a positive effect on performance when firms using external knowledge have higher absorptive capacity. We find general support for our hypotheses, which we test using patent citation data from the global integrated circuit manufacturing industry. Our findings have important implications for managers of firms making strategic decisions about their firms’ product portfolios and the degree to which they use external knowledge.     

Standards, critical mass, and the formation of complex industries: A case study of the mobile Internet

This is one of the few papers to analyze multiple interface standards in a single industry and it finds that standard setting in such an industry is much more complex than those covered in the existing literature. In the mobile Internet, some of the interface standards initially required so-called integral design while others have been built on top of these “basic” interface standards. The former interface standards enable basic data connections between phones, services, and content while the latter ones connect the mobile phone with content and applications from other industries such as music, video, publishing, broadcasting, and payment. This paper shows that in connecting the mobile phone and other industries, each critical mass of phones, services, and content partly builds from previously created critical masses.     

WHY DO EMERGING ECONOMIES BORROW SHORT TERM?

We argue that one reason why emerging economies borrow short term is that it is cheaper than borrowing long term. This is especially the case during crises, as during these episodes the relative cost of long‐term borrowing increases. We construct a unique database of sovereign bond prices, returns, and issuances at different maturities for 11 emerging economies from 1990 to 2009 and present a set of new stylized facts. On average, these countries pay a higher risk premium on long‐term than on short‐term bonds. During crises, the difference between the two risk premia increases and issuance shifts towards shorter maturities. To illustrate our argument, we present a simple model in which the maturity structure is the outcome of a risk‐sharing problem between an emerging economy subject to rollover crises and risk‐averse international investors.     

JEEA‐FBBVA LECTURE 2013: THE NEW EMPIRICAL ECONOMICS OF MANAGEMENT

Over the last decade the World Management Survey (WMS) has collected firm‐level management practices data across multiple sectors and countries. We developed the survey to try to explain the large and persistent total factor productivity (TFP) differences across firms and countries. This review paper discusses what has been learned empirically and theoretically from the WMS and other recent work on management practices. Our preliminary results suggest that about a quarter of cross‐country and within‐country TFP gaps can be accounted for by management practices. Management seems to matter both qualitatively and quantitatively for performance at the level of the firm and the nation. Competition, governance, human capital, and informational frictions help account for the variation in management. We make some suggestions for both policy and future research.