Adaptive multiple importance sampling for Gaussian processes

In applications of Gaussian processes (GPs) where quantification of uncertainty is a strict requirement, it is necessary to accurately characterize the posterior distribution over Gaussian process covariance parameters. This is normally done by means of standard Markov chain Monte Carlo (MCMC) algorithms, which require repeated expensive calculations involving the marginal likelihood. Motivated by the desire to avoid the inefficiencies of MCMC algorithms rejecting a considerable amount of expensive proposals, this paper develops an alternative inference framework based on adaptive multiple importance sampling (AMIS). In particular, this paper studies the application of AMIS for GPs in the case of a Gaussian likelihood, and proposes a novel pseudo-marginal-based AMIS algorithm for non-Gaussian likelihoods, where the marginal likelihood is unbiasedly estimated. The results suggest that the proposed framework outperforms MCMC-based inference of covariance parameters in a wide range of scenarios.     

The Principal Statistical Sources for the Labour Market in Italy

ABSTRACT: The state of disequilibrium which the labour market in Italy (as in all the major industrialised countries) presents, has been the centre of debate in political and economic circles for many years now. How should this disequilibrium be interpreted, considering the complexity of the phenomena found in the labour area? Can they be modeled into global explanatory schemas of general economic theory? The authors believe the complexity of these phenomena can neither be ignored nor simplified, but accepted as a distinguishing feature of the labour market, and thus have to be interpreted on the basis of numerous and often contradictory control variables. This paper hence outlines the principle sources of Italian labour market data available, in order to provide a rational and critical guide to interpreting the available indicators. The sources examined are both institutional (the ISTAT and Ministry of Labour surveys) and private (the employers associations of Confindustria, Assolombarda and Federmec-canica). The paper outlines the areas covered, the methodology, and the qualities and drawbacks that these surveys present.     

Wages and Unemployment in Italy,a Long Term Perspective

ABSTRACT: This paper traces a long-term perspective of the relationship between wages and unemployment in the Italian economy from the end of the fifties to the mid-eighties. During this period, the rate of unemployment exhibited three distinct time profiles. After a cyclical episode from around 1958 to the mid-sixties, the unemployment rates changed very little for a decade, showing only mild fluctuations until 1975. Since then, unemployment has been increasing steadily, and in 1987 it exceeded 12|X% of the labour force. The aim of this paper is not to provide a new interpretation of facts, but rather to assess whether, and when, wage pressure has represented a significant factor in the evolution of unemployment. The main conclusion of the paper is that the considerable rise in unemployment observed since the mid-70s is part of a long term evolution, and that in the long-run wages are not exogenous. Though there have been periods of exogenous wage push temporarily affecting unemployment, the argument that the continuous rise in unemployment depends on inappropriate real wages has no empirical content.     

Economic versus psychological forecasting. Evidence from consumer confidence surveys

Permanent and widespread psychological biases affect both the subjective probability of future economic events and their retrospective interpretation. They may give rise to a systematic gap between (over-critical) judgments and (over-optimistic) expectations – the “forecast” error. When things go bad, then, psychology suggests that people tend to become particularly bullish, amplifying the forecast error. Also, psychology argues that personal/future conditions are systematically perceived to be better than the aggregate/past ones. All this sharply contrasts with standard economic assumptions. Evidence from a unique dataset covering 10 European countries over 22 years confirms the presence of structural psychologically driven distortions in people’s judgments and expectations formation.     

Agency costs of free cash flow,internal capital markets and unrelated diversification

This paper investigates whether free cash flow arguments or the internal capital market perspective better explains diversification decisions. Based on a unique panel of hand-collected data from listed and unlisted Italian firms for the 1980–2010 time period, the results of this study generally reveal the predominant role of the internal capital market arguments. The benefits of unrelated diversification, which include the avoidance of costly external financing, outweigh its costs, which involve opportunistic problems. Although the literature suggests two distinct forces concurrently affect diversification decisions, in the Italian context, financial benefits appear to be the prevailing motivation for unrelated diversification decisions. Furthermore, the internal capital market argument has a strong effect on decisions to engage in unrelated diversification, particularly with respect to firms that are sensitive to financial constraints.     

The corporate planner as consultant

The role of consultancy, in contrast to other interactive roles at central staff level, is tied to personal and professional relationships and the credibility of the service hinges on skills and direct personal relationships and not on a structure. This article focuses on a ‘planning idea’ involving the restructuring of the planning procedure and a de-emphasis on the role of staff.     

The Difficult History of Ancillary Units: The Obstacles and Potential Opportunities to Increase the Heterogeneity of Neighborhoods and the Flexibility of Households in the United States

ABSTRACT

Most aging Americans express the desire to stay in their current home for the rest of their lives. However, as literature and practice indicate, aging in place cannot be successfully achieved in all places, especially in those places where zoning regulations and building codes act as barriers to the flexible adaptation of environments. One possible solution could come from the legalization of what is commonly known as granny flats, or more technically as Ancillary Dwelling Units. This article is divided into three parts. The first part is a brief history of Ancillary Dwelling Units. The second part focuses on the critical role played by local and state urban planning policies in the future of Ancillary Dwelling Units. California is used as a noteworthy example. The third part discusses how positive outcomes for senior residents who have Ancillary Dwelling Units legally present in their neighborhoods are linked to the appropriateness of their design.     

Understanding the socio-economic distribution of multiple deprivation: An application of self-organising maps

In this paper we seek to contribute to recent efforts to develop and implement multi-dimensional approaches to social exclusion by applying self-organising maps (SOMs) to a set of material deprivation indicators from the Irish component of EU-SILC. The first stage of our analysis involves the identification of sixteen clusters that confirm the multi-dimensional nature of deprivation in contemporary Ireland and the limitations of focusing solely on income. In going beyond this mapping stage, we consider both patterns of socio-economic differentiation in relation to cluster membership and the extent to which such membership contributes to our understanding of economic stress. Our analysis makes clear the continuing importance of traditional forms of stratification relating to factors such as income, social class and housing tenure in accounting for patterns of multiple deprivation. However, it also confirms the role of acute life events and life cycle and location influences. Most importantly, it demonstrates that conclusions relating to the relative impact of different kinds of socio-economic influences are highly dependent on the form of deprivation being considered. Our analysis suggests that debates relating to the extent to which poverty and social exclusion have become individualized should take particular care to distinguish between different kinds of outcomes. Further analysis demonstrates that the SOM approach is considerably more successful than a comparable latent class analysis in identifying those exposed to subjective economic stress.     

Jochen Roose: Die Europäisierung von Umweltorganisationen. Die Umweltbewegung auf dem langen Weg nach Brüssel

KZfSS Kölner Zeitschrift für Soziologie und Sozialpsychologie -