SOME REPARAMETERIZATIONS OF LAG POLYNOMIALS FOR DYNAMIC ANALYSIS

ABSTRACT Various reparameterizations of scalar polynomials are considered in the context of lag polynomials. These are used to explore possibilities of testing for stationary autoregressive roots, repeated roots, and polynomial factors of given form. Multivariate generalizations of these results are then applied to VAR models and to comovement between the component series of such systems. The link between the representation of unitroots in the univariate case and cointegration in multivariate systems is demonstrated.     

SOME PRACTICAL GUIDANCE FOR THE IMPLEMENTATION OF PROPENSITY SCORE MATCHING

Abstract Propensity score matching (PSM) has become a popular approach to estimate causal treatment effects. It is widely applied when evaluating labour market policies, but empirical examples can be found in very diverse fields of study. Once the researcher has decided to use PSM, he is confronted with a lot of questions regarding its implementation. To begin with, a first decision has to be made concerning the estimation of the propensity score. Following that one has to decide which matching algorithm to choose and determine the region of common support. Subsequently, the matching quality has to be assessed and treatment effects and their standard errors have to be estimated. Furthermore, questions like ‘what to do if there is choice‐based sampling?’ or ‘when to measure effects?’ can be important in empirical studies. Finally, one might also want to test the sensitivity of estimated treatment effects with respect to unobserved heterogeneity or failure of the common support condition. Each implementation step involves a lot of decisions and different approaches can be thought of. The aim of this paper is to discuss these implementation issues and give some guidance to researchers who want to use PSM for evaluation purposes.     

SOME EVIDENCE FOR AN INTERNATIONAL MANAGERIAL CULTURE

An analysis is reported of the relations between the semantic responses obtained from managers of four nationalities. A total of 365 expatriate and local managers in the Singaporean subsidiaries of 34 American, British and Japanese M.N.C.s assessed their own and each of the other groups along each of 18 adjectival antonym pairs. For each nationality the correlations between the semantic items are used as similarity data for multidimensional scaling of the adjectives. It is shown that the 18 adjectival pairs can be reduced to a two-dimensional circular map for each nationality, and that the placing of the adjectives on the circle agrees with a root mean square misfit of about 10° for the four nationalities. The results support the hypothesis that, for the groups considered, a shared international culture exists in the managerial context. The two dimensions on which the 36 semantic items can be mapped are interpretable as functional/dysfunctional and open/closed.     

THE ORGANIZATIONAL CORRELATES AND CONSEQUENCES OF SUBCONTRACTING: EVIDENCE FROM A SURVEY OF SOUTH WALES BUSINESSES

Recent interest in the growth of subcontracting, as part of a broader trend towards greater ‘flexibility’in forms of employment relationship, has not as yet been matched by a full consideration of its organizational and managerial implications. In particular, the question of whether or not subcontracting has an impact upon, or is affected by, the organization's structural characteristics remains largely unexplored. the aim of this article is to report findings from a detailed study of subcontracting practices across a sample of British industry, which focuses upon the relationship between subcontracting and organizational characteristics. the results indicate several important points about the practice. Firstly, that there is wide variation in the use of subcontracting across industry, although the overall extent is limited. Secondly, that variation in the practice is significantly related to basic firm characteristics - namely, industrial sector, type of production system and pattern of ownership and control. Thirdly, that, on balance, subcontracting is associated with more, not less, structural complexity. Finally, that this greater complexity is found in particular types of firms - notably, outside the manufacturing sector, in mass and process production systems and amongst British independents and subsidiaries, rather than in their foreign competitors.     

LOW-INCOME HOUSING IN INDIAN CITIES: SOME CONSIDERATIONS FOR POLICY

Across cities in India, migrant groups, squatters and the urban poor residing in slums have played a crucial role in developing low-income housing. This form of housing is closely connected to the economic activity of the poor, which in turn contributes to the wider urban economy. It also enables the poor to consolidate their position in the city and make claims on the city administration for infrastructure. However, such housing has been bracketed as 'informal' and lacks legitimacy. Policies concerning low-income housing must address this issue while enabling the poor to further their economic and entrepreneurial initiatives.     

ORGANIZATIONAL ADAPTATION: SOME IMPLICATIONS OF ORGANIZATIONAL ECOLOGY FOR STRATEGIC CHOICE[1]

This article identifies a correspondence between the organizational ecology and strategic choice perspectives on organizational strategy in their classifications of strategic types. Using this correspondence as the point of departure, implications of organizational ecology for strategic choice are examined with respect to how environmental pressures constrain strategic choice, why some strategic orientations are more successful than others in different environmental conditions, and how and why the mix of strategic types in an industry changes over time.     

THE ‘COMPARATIVE INSTITUTIONAL’ THEORY OF THE FIRM: SOME IMPLICATIONS FOR CORPORATE STRATEGY*

This article outlines a rationale for the existence of firms and derives its implications for corporate strategy. It argues that one important source of sustainable rents is the ability of firms to reduce the costs they experience in organizing both internal and external transaction below those of their rivals.     

COGNITIVE MAPPING AND REPERTORY GRIDS FOR QUALITATIVE SURVEY RESEARCH: SOME COMPARATIVE OBSERVATIONS

A study of business strategy was carried out in 86 organizations in the crop protection industry. A multi-operational approach was used to enable validation of data by triangulation, including cognitive mapping used in an unusual way. This provided an unintended opportunity to conduct a comparative evaluation of interactive investigational methods in a relatively controlled, if unsophisticated manner. Results were interesting enough to suggest that further investigation is needed into the impact of various subject-generated factors such as face validity on methodological effectivness, as well as more traditional criteria such as construct validity of particular methods. Accordingly, process issues affecting repertory grids, cognitive mapping and software for the analysis of cognitive maps (COPE) are described and discussed. Recommendations are made for improvements to mapping and software and further studies suggested.     

A COMPARISON OF SOME INTRODUCTORY AND UNDERGRADUATE ECONOMETRIC TEXTBOOKS

Books reviewed in this article:
William H. Greene (1993) Econometric Analysis (Second Edition)
William E. Griffiths, R. Carter Hill and George G. Judge (1993) Learning and Practicing Econometrics
George G. Judge, R. Carter Hill, William E. Griffiths, Helmut Lütkepohl and Tsoung-Chao Lee (1988) Introduction to the Theory and Practice of Econometrics (Second Edition)
G. S. Maddala (1992) Introduction to the Theory and Practice of Econometrics (Second Edition)     

PREDICTING NEGATIVE EFFECTS OF THE SECOND INTIFADA: AN EX-POST EVALUATION OF SOME MODELS

In 2003, the World Bank (WB), the International Monetary Fund (IMF) and de Boer and Missaglia (DBM) constructed models for the estimation of the 2002 macro-economic indicators of the economy of Palestine. In 2007, IMF and WB provided the consensus estimates of these figures using data that are more up-to-date and more complete than those available in 2003. This note proposes an ex-post evaluation of the predictive performance of the models of WB, DBM and IMF. A comparison of the models of WB and DBM, which are both micro-founded computable general equilibrium models using the same data, reveals that DBM strongly outperforms WB. We argue that the shortening of the time horizon and the quantity adjustment following the dramatic shock explain why our model performs much better. A comparison of DBM with IMF (a simple macro-founded income-expenditure model) also shows that our model performs better.