Estimating the Spot Covariation of Asset Prices—Statistical Theory and Empirical Evidence

ABSTRACT

We propose a new estimator for the spot covariance matrix of a multi-dimensional continuous semimartingale log asset price process, which is subject to noise and nonsynchronous observations. The estimator is constructed based on a local average of block-wise parametric spectral covariance estimates. The latter originate from a local method of moments (LMM), which recently has been introduced by Bibinger et al.. We prove consistency and a point-wise stable central limit theorem for the proposed spot covariance estimator in a very general setup with stochastic volatility, leverage effects, and general noise distributions. Moreover, we extend the LMM estimator to be robust against autocorrelated noise and propose a method to adaptively infer the autocorrelations from the data. Based on simulations we provide empirical guidance on the effective implementation of the estimator and apply it to high-frequency data of a cross-section of Nasdaq blue chip stocks. Employing the estimator to estimate spot covariances, correlations, and volatilities in normal but also unusual periods yields novel insights into intraday covariance and correlation dynamics. We show that intraday (co-)variations (i) follow underlying periodicity patterns, (ii) reveal substantial intraday variability associated with (co-)variation risk, and (iii) can increase strongly and nearly instantaneously if new information arrives. Supplementary materials for this article are available online.     

PATHS AND SEMIPATHS: RECONCEPTUALIZING STRUCTURAL COHESION IN TERMS OF DIRECTED RELATIONS

In a groundbreaking article, Moody and White (2003) introduced the concept of structural cohesion, simultaneously characterizing emergent communities and their internally embedded layers by the number of node-independent paths interconnecting individuals. Like many studies, however, they "corrected" the directionality discovered in some of their data. While often done for important purposes, doing so potentially confounds structural cohesion with unrelated concepts. Some relations, especially those relating to the dynamic aspects of social life, are inherently directed, in whole or in part, and it may prove worthwhile to respect this directionality. In this article, I recast structural cohesion in terms of directed social relations and identify four distinct ways of measuring it. In two example data sets—hiring relations among graduate programs and trust relations among neighborhood residents—I show that only strong embeddedness, a type of structural cohesion emerging from directed relations, proves to be a powerful, robust, independent explanatory factor. I further show that if the directionality in the data in these examples had been "corrected," the importance of structural cohesion would have been dramatically undervalued.     

UNIVERSITY ADMINISTRATORS, AGRICULTURAL BIOTECHNOLOGY, AND ACADEMIC CAPITALISM: Defining the Public Good to Promote University–Industry Relationships

The theory of academic capitalism explains how federal, state, and university policies and people have expanded university–industry relationships (UIRs) and the commercialization of knowledge. These changes represent a profound shift in the way university research is expected to contribute to the public good. Because university administrators are responsible for creating organizational policies and infrastructures that are consistent with their organizational mission and with federal and state laws, it is critical to analyze how university administrators assess UIRs in relation to public-interest scientific research. Our in-depth interviews at six prominent land-grant universities with 59 key administrators having oversight responsibilities for agricultural biotechnology research programs and UIRs reveal how administrators justify their role in promoting UIRs. They tend to interpret their university's mission to contribute to the public good in a way that is conducive to encouraging UIRs and to commercializing research discoveries. Their rationale emerges within a context of having to justify their budgets to state governments.     

A Nonparametric Estimator of Survival Functions for Arbitrarily Truncated and Censored Data

It is well-known that the nonparametric maximum likelihood estimator (NPMLE) may severely under-estimate the survival function with left truncated data. Based on the Nelson estimator (for right censored data) and self-consistency we suggest a nonparametric estimator of the survival function, the iterative Nelson estimator (INE), for arbitrarily truncated and censored data, where only few nonparametric estimators are available. By simulation we show that the INE does well in overcoming the under-estimation of the survival function from the NPMLE for left-truncated and interval-censored data. An interesting application of the INE is as a diagnostic tool for other estimators, such as the monotone MLE or parametric MLEs. The methodology is illustrated by application to two real world problems: the Channing House and the Massachusetts Health Care Panel Study data sets.     

Economic Conditions in Rome and Their Lessons for Us

Abstract

The Economic and Social History of an English Village (Crawley, Hampshire) A.D. 909-1928. By N. S. B. Gras and E. C. Gras. Harvard University Press, Cambridge, 1930, XV, 730 pp. $7.50.

The American Revolution and the British Empire. By R. Coupland. Longmans, Green and Co. London, New York, Toronto, 1930; vii, 331 pp. $4.50. Reviewed by Robert Livingston Schuyler.

The Genius of Mexico. Lectures Delivered before the Fifth Seminar in Mexico, 19.10. Edited by Hubert C. Herring and Katharine Terrill. The Committee on Cultural Relations with Latin America, New York, 1931. 334 pp. Reviewed by Milton W. Hamilton.

A Guide to the Study of Medieval History. By Louis J. Paetow. Revised Edition under the Auspices of the Medieval Academy of America, Dana C. Munro, editor in chief. New York, 1931. (Crofts, $6.00). Reviewed by John L. La Monte.

International Government. By Edmund C. Mower. D. C. Heath &; Co., Boston, 1931. xix, 736 pp. $5.00.

International Law. A Restatement of Principles in Conformity with Actual Practise. By Ellery C. Stowell. Henry Holt &; Co., New York, 1931. xxvi, 829 pp. $4.75. Reviewed by Walden Moore.

A History of South America. By Charles Edmund Akers. E. P. Dutton and Co., New York, 1930. xxxii, 781 pp. Illus. Maps. $5.

A History of the Argentine Republic. By F. A. Kirkpatrick. Cambridge University Press, Cambridge, 1931. xxvii, 255 pp. Illus. Maps.

Narratives of the Discovery of America. By A. W. Lawrence and Jean Young. Jonathan Cape and Harrison Smith, New York, 1931. viii, 300 pp. Maps. $3.

Select Documents Illustrating the four Voyages of Columbus. Vol. 1. By Cecil Jane. The Hakluyt Society, London, 1930. Illus. Maps. Reviewed by A. Curtis Wilgus.

The American Public Mind. By Peter Odegard. Columbia University Press, New York, 1930. 308 pp.

American Society. By Charles F. Thwing. The Macmillan Company, New York, 1931. 271 pp. Reviewed by R. Stanley McCordock.

The Cabinet Council of England in the Seventeenth and Eighteenth Centuries, 1622-1784, vol. 1. By Edward Raymond Turner. The Johns Hopkins Press, Baltimore, 1930. xi, 469 pp. $7.50. Reviewed by Charles F. Mullett.

A History of the Hebrew People from the Earliest Times to the Year 70 A.D. Largely in the Language of Bible. Prepared by George A. Barton. The Century Co., New York, London, 1930, 464 pp. $3.50. Reviewed by Salo Baron.

Nelson W. Aldrich: a Leader in American Politics. By Nathaniel Wright Stephenson. Charles Scribner's Sons, New York, 1930. xii, 496 pp. Reviewed by Herbert B. Howe.     

Attachment and emotion regulation: Compensatory interactions and leader–member exchange

The current study draws on attachment theory (Bowlby, 1982) to examine how attachment (a relationship-based trait disposition), and the interaction between attachment and emotion regulation, relate to LMX quality. Data were collected from subordinates and supervisors in a variety of work settings. Attachment anxiety and attachment avoidance negatively predicted LMX quality. Moderator effects were found between attachment and emotion regulation.     

Author disincentives and open access

Abstract

All parties in the scholarly-information marketplace agree that any Open Access (OA) system will have to account for the costs of disseminating scholarly information and of editing, publishing and distributing it. There has been less discussion of the fact that for an OA forum to succeed, it will have to be accepted and supported by authors. Author charges, a relative lack of prestige, and the required abdication of copyright are three characteristics of many currently emerging OA models that may pose significant barriers to author acceptance. These will have to be addressed if OA providers wish to be competitive with non-OA providers.     

Web-assisted instruction for changing social cognitive variables related to physical activity

The authors examined the efficacy of Web-assisted instruction for promoting the use of social cognitive theory (SCT) strategies related to physical activity. They recruited college students attending health courses. The authors created 3 groups (Web-assisted, comparison, and control) based on the course structure. The Web-assisted group received information on exercise and fitness and a Web-based program (treatment, n = 127); 7 sections received the same exercise and fitness information as the treatment condition, but no Web-based program (comparison, n = 118); and 6 sections received information in unrelated areas (control, n = 178). The Web-based program consisted of 9 Web assignments (1 per week) that targeted key SCT variables. Satisfaction with the Web-based program was high. Use of self-regulation strategies was significantly higher at posttest in the treatment group than it was in the other groups. Knowledge concerning the skills taught by the Web assignments was significantly greater in the treatment group than it was in the comparison group. The results of this study demonstrate that a Web-based instructional program has a positive impact on knowledge and skills related to SCT strategies for changing physical activity behavior.     

Generalized Haber's Law for Exponential Concentration Decline,with Application to Riparian‐Aquatic Pesticide Ecotoxicity

A simple analytic solution to the dynamic version of Haber's law was derived, conditional on a specified toxic load exponent (n) and on exponential decline in environmental toxicant concentration. Such conditions are particularly relevant to assessing ecotoxicity risk posed (e.g., to juvenile salmonids) by agricultural organophosphate (OP) pesticides that are subject to degradation and/or dissipation. A dynamic Haber's law model was fit to previously published detailed data on lethality for two aquatic species induced by six agricultural OP pesticides, and more crude fits were obtained to less detailed data on five other OP and on two non‐OP pesticides, indicating that for lethality, a range of 0.5 ≤ n ≤ 1.5 may be typical for OP pesticides. The AgDRIFT^® stream deposition model was next used to establish that first‐order or exponential loss, with dilution half‐times on the order of ≤0.01 days, pertains approximately to pesticide residues in streams that arise after aerial application of agricultural pesticides 100 feet upwind. The analytic model was then applied to demonstrate that pesticide concentrations deposited in downwind streams following an aerial application are effectively diluted by about 50‐ to 300‐fold from their initial concentration. Riparian ecotoxicity risk assessment models that ignore this effective dilution, and base pesticide‐specific estimates of reduced survival on the initial concentrations, are therefore unrealistically conservative.