Sample attrition in the RLMS, 2001–10

The data of the Russian Longitudinal Monitoring Survey (RLMS) – Higher School of Economics represents one of the few nationally representative sources of household and individual data for Russia. These data have been collected since 1992 and in recent years, thanks to more secure financial and logistical support, have become a resource increasingly drawn upon by scholars and students for national and cross-national studies. In this paper, we examine the extent of non-random attrition in the RLMS and discuss the circumstances under which this might give rise to biases in econometric analysis. We illustrate this with an example drawn from the health sphere.     

Visual displays: analytical study and applications to graphs and real data

Principal axis methods such as principal component analysis (PCA) and correspondence analysis (CA) are useful for identifying structures in data through interesting planar graphic displays. However, some kinds of data sets can be dealt alternatively with PCA or CA. This paper focuses on methods, such as PCA and CA, and on visual displays. Our aim is to illustrate the implications for a potential user of selecting either method, and its advantages and disadvantages, from an applied point of view. This is a matter covered broadly in textbooks and elsewhere considering theoretical arguments. Our purpose is to contribute to the comparison between these methods, over the same data set, in order to illustrate them for the practitioner. In the first part of this paper we present a novel analytical study of a binary matrix associated with a non-oriented axis-symmetric graph and show that CA outperforms standardized PCA for the reconstitution and visualization of such kind of graphs. In the second part we present a case using real data dealing with the distribution of employees in different economic sectors for the countries of the European Union, analyzed by means of standardized PCA and two-way CA, in order to see the differences between the two methods in practice.     

Asymptotic behaviour of tests for a unit root against an explosive alternative

We compare the asymptotic local power of upper-tail unit root tests against an explosive alternative based on ordinary least squares (OLS) and quasi-differenced (QD) demeaning/detrending. We find that under an asymptotically negligible initialisation, the QD-based tests are near asymptotically efficient and generally offer superior power to OLS-based approaches; however, the power gains are much more modest than in the lower-tail testing context. We also find that asymptotically non-negligible initial conditions do not affect the power ranking in the same way as they do for lower-tail tests, with the QD-based tests retaining a power advantage in such cases.     

Core Requirements for the Economics Major

In this article, the authors are the first to describe the core economics curriculum requirements for economics majors at all American colleges and universities, as opposed to a sample of institutions. Not surprisingly, principles of economics is nearly universally required and implemented as a two-semester course in 85 percent of economics major programs. Most schools do not prescribe the order in which the principles sequence is taken. The intermediate courses are commonly required, although variation exists across institution types. While the quantitative requirement for the major has increased since 1980, significant differences exist among institutions and by academic rankings. As compared to 1950, there has been an increase in the number of required economics credit hours for the major.     

Do city–county mergers in China promote local economic development?

Municipal mergers have become a worldwide phenomenon in the past few decades, primarily advanced to exploit economies of scale. While most evaluations of municipal mergers have focused on the efficiency of local public goods provision, it is rare in the literature to explore how such mergers promote economic growth in a developing country context. This research investigates the economic consequences of a policy experiment of city–county mergers (che xian she qu) in China during the period 2000–2004. Using comprehensive datasets at city, county and firm levels, we present evidence that the merger significantly increases local economic development, and the magnitude of the effect depends on local endowments related to agglomeration forces. The results are robust to a number of different model specifications. We further verify that improved transport infrastructure and urban agglomeration economies after merger are potential contributors to the positive merger effects.     

Inference of the Russian drug community from one of the largest social networks in the Russian Federation

The criminal nature of narcotics complicates the direct assessment of a drug community, while having a good understanding of the type of people drawn or currently using drugs is vital for finding effective intervening strategies. Especially for the Russian Federation this is of immediate concern given the dramatic increase it has seen in drug abuse since the fall of the Soviet Union in the early nineties. Using unique data from the Russian social network ‘LiveJournal’ with over 39 million registered users worldwide, we were able for the first time to identify the on-line drug community by context sensitive text mining of the users’ blogs using a dictionary of known drug-related official and ‘slang’ terminology. By comparing the interests of the users that most actively spread information on narcotics over the network with the interests of the individuals outside the on-line drug community, we found that the ‘average’ drug user in the Russian Federation is generally mostly interested in topics such as Russian rock, non-traditional medicine, UFOs, Buddhism, yoga and the occult. We identify three distinct scale-free sub-networks of users which can be uniquely classified as being either ‘infectious’, ‘susceptible’ or ‘immune’.     

Modeling the Transition from Enhanced Oil Recovery to Geologic Carbon Sequestration

Policy debates suggest a future role for geologic carbon sequestration. As geologic sequestration (GS) evolves from enhanced oil recovery operations to an emissions‐mitigation option, regulations must evolve to manage the risks of carbon dioxide (CO₂) migration. We develop an engineering‐economic model to understand the key deployment pathways in this transition. Major results reveal that dedicated CO₂ storage in aquifers is associated with the greatest net revenues under only a limited number of scenarios. This finding suggests that regulators should anticipate GS operations in reservoirs that were not initially intended as GS operations and, therefore, may have higher leakage rates. Copyright © 2013 John Wiley & Sons, Ltd.