The skill profile of the employees and the provision of flexible working hours in the workplace: a multilevel analysis across European countries

This article investigates the relationship between the skill profile of the employees (i.e. the percentage of employees in highly skilled jobs) and the provision of flexible working hours in the workplace (i.e. the proportion of employees entitled to adapt, within certain limits, the time when they begin or finish their daily work according to their personal needs or wishes). Analyses draw on the 2009 European Company Survey, conducted on a representative sample (N = 26,640) of European establishments in 29 countries. Multilevel mixed‐effects linear regressions are used to study to what extent both workplace‐level and national‐level variables affect this relationship. Findings suggest a strong, positive and non‐linear relationship between the variables under scrutiny, which is moderated, at national level, by both unemployment and trade union density rates.     

Consistent recalibration of yield curve models

The analytical tractability of affine (short rate) models, such as the Vasi?ek and the Cox–Ingersoll–Ross (CIR) models, has made them a popular choice for modeling the dynamics of interest rates. However, in order to properly account for the dynamics of real data, these models must exhibit time‐dependent or even stochastic parameters. This breaks their tractability, and modeling and simulating become an arduous task. We introduce a new class of Heath–Jarrow–Morton (HJM) models that both fit the dynamics of real market data and remain tractable. We call these models consistent recalibration (CRC) models. CRC models appear as limits of concatenations of forward rate increments, each belonging to a Hull–White extended affine factor model with possibly different parameters. That is, we construct HJM models from “tangent” affine models. We develop a theory for continuous path versions of such models and discuss their numerical implementations within the Vasi?ek and CIR frameworks.     

Reorganizing web sites based on user access patterns

In this paper, an approach for reorganizing Web sites based on user access patterns is proposed. Our goal is to build adaptive Web sites by evolving site structure to facilitate user access. The approach consists of three steps: preprocessing, page classification, and site reorganization. In preprocessing, pages on a Web site are processed to create an internal representation of the site. Page access information of its users is extracted from the Web server log. In page classification, the Web pages on the site are classified into two categories, index pages and content pages, based on the page access information. After the pages are classified, in site reorganization, the Web site is examined to find better ways to organize and arrange the pages on the site. An algorithm for reorganizing Web sites has been developed. Our experiments on a large real data set show that the approach is efficient and practical for adaptive Web sites. Copyright © 2002 John Wiley & Sons, Ltd.     

Accumulation of knowledge and increasing returns in neoclassical models

In the mid 1980s there was a remarkable revival of interest in growth theory. A relevant strand of new literature is characterized by the departure from the assumption of diminishing returns of capital or, more generally, of the accumulated factor. In this paper we will see how the neoclassical theorists incorporated the idea of increasing returns in the formal models of economic growth, already an important question in the sixties. The central point is that the recent recognition of the importance of this notion is not new but now depends on the vision of economic growth as driven by knowledge accumulation and no longer by capital accumulation as in the Solovian tradition. I would like to thank the referee for valuable comments and suggestions.     

Forme multilineari ed approssimate di funzioni di utilità di due variabili

Nella prima parte di questo lavoro, definita l'indipendenza tra gli attributi di una funzione di utilità di due variabiliu(x, y) si determinano forme multilineari del tipou(x, y) = ₁ u ₁ (x) + ₂ u ₂ (y) + ₁₂ u ₁ (x)u ₂ (y) e se ne studiano le proprietà.Successivamente si propongono alcune approssimazioni diu(x, y) e si verifica quali proprietà fondamentali degli ordinamenti di preferenza esse conservano. In entrambi i casi si ottengono delle forme la cui utilità acquista rilevanza nella semplificazione operativa nei problemi di decisione in condizioni di incertezza.

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Here we propose two different methods to overcome the pratical difficulties present in the application of two-attribute utility functions in decision problems under uncertainty. The first method consists in deriving them through modified preference axioms, whereas the second deals with their numerical approximations without violating the fundamental properties of preference ordering.

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Lavoro eseguito nell'ambito del C.N.R.-G.N.A.F.A.     

Components of effective devaluation and the domestic rate of inflation: The case of Israel

Developing countries have frequently resorted to effective devaluation by changing either their formal rate of exchange, or by using non-formal components, such as taxes and subsidies. The ensuing increase in the domestic price of imports has inflationary effects. This paper analyses the Israeli experience to investigate the inflationary effects of increases in import prices and alternative methods of devaluation. It is found that formal and non-formal devaluation appear to have the same long-run effects on the price level, but are not the same in timing: A formal devaluation leads more quickly to increases in domestic prices.