Are newsgroups extending "invisible colleges" into the digital infrastructure of science?

This paper contributes to the debate on the influence of electronic communication on the informal exchange of information among scientists and practitioners. The research is focused on an empirical analysis of three specialised Newsgroups in "speech technology" (comp.speech, comp.speech.research and comp.speech.users), over the period 1992-2000. Looking at these discussion forums as electronic systems of social interaction, it is appropriate to ask whether they are extending the traditional social networks of "invisible colleges" into the digital age? This paper concludes that this is indeed occurring. First, to a significant extent these electronic environments support international and inter-sectoral remote collaboration. Secondly, these forums support the creation of key properties of "invisible colleges", persistent interaction among peers and a "division of labour" in the accumulation of expertise. Both of these properties are supported by a longitudinal network analysis of the forums. Further opportunities for inquiry are discussed in the concluding section.     

Diversity of innovation patterns in services

Recently, literature on innovation in service activities has increased significantly. Much effort has been concentrated on understanding the importance of innovation for these activities, and on stressing innovative differences relative to the manufacturing innovation model. However, a deeper understanding is needed in three main areas: the degree of innovation heterogeneity among different service activities, the factors that explain this heterogeneity, and the primary drivers of the innovation process for each activity. Using results from the Third Community Innovation Survey, this paper aims to identify the extent to which there are similarities and differences in the main innovation attributes in four important service sub-sectors. After describing the characteristics of innovation and the behavior of variables in the sub-sectors, a typology of innovation patterns is identified.     

Re-scaling risk governance using local appraisal and community involvement

This paper describes a risk governance model applied on a local scale, showing the advantages and constraints found during its application. The risk governance model, built on a municipal scale, results from the application of the International Risk Governance Council framework. The model is characterised by the cyclicity between the assessment and management spheres, assuming communication to be essential in all stages. Its application in central Portugal is rooted in a specific knowledge of hazards and their impacts, the human and financial constraints, and the expectations of citizens and stakeholders. The results show that preformatted management solutions derived from national civil protection stakeholders can be adapted to a local physical, social and institutional context. It was found that this depends significantly on the stakeholders’ concerns assessment, as this allows the subsequent risk management options to be adapted and legitimised. As a result, more appropriate land-use regulations and mitigation strategies are being designed, which are related to urban planning, road design, risk sensitisation and communication tools. However, two features are likely to lead to an overlapping of competences and conflicts concerning responsibility for decision-making in the actual civil protection structure: the current constraints on resources on an operational level and the potentially inadequate representation of stakeholders on a strategic level.     

Institutions and growth: evidence from estimation methods robust to weak instruments

This article focuses on the empirical approach proposed by Hall and Jones (1999 Hall, RE and Jones, CI(HJ99). 1999. Why do some countries produce so much more output per worker than others?. The Quarterly Journal of Economics, 114: 83–116. [Crossref], [Web of Science ®] , [Google Scholar]) to estimate the effect of what they call ‘social infrastructure’ on productivity across countries. We consider the issue of weak identification in their linear instrumental variables model. The evidence obtained from partially robust estimators, such as the k-class and jackknife estimators, is interpreted on the basis of Monte Carlo studies. Our findings suggest that using certain k-class estimators allows exclusive reliance on the linguistic variables to instrument for institutional quality despite their low correlation with the endogenous regressor in question.     

What keeps pensioners at work in Russia? Evidence from Household Panel Data

The proportion of working pensioners in Russia is high relative to what is usually observed in several Eastern and Western European countries. In this paper, we present an analysis of the determinants of pensioner employment, using panel data from the on-going Russian Longitudinal Monitoring Survey for the period 1994-99. Given the sharp deterioration in the safety net in recent years, a particular attempt is made to assess the role of inadequate pension benefits, along with other individual, household, and local labour market characteristics, in driving up the employment rate of older people during transition. Both the probability of holding a job and the number of hours worked are modeled. The microeconometric analysis confirms the role that family income and access to alternative coping mechanisms such as subsistence farming play in pensioner employment for women, but also stresses for both men and women the importance of age, education, and health status. Finally, the results show a low sensitivity of pensioner employment to pension arrears and pension benefits, indicating that even the full payment of benefits may be too low to significantly affect the decision to remain in employment.
JEL classification: C33, H55, J14, J21, P36.     

Online advertising and privacy

An online platform auctions an advertising slot. Several advertisers compete in the auction, and consumers differ in their preferences. Prior to the auction, the platform decides whether to allow advertisers to access information about consumers (disclosure) or not (privacy). Disclosure improves the match between advertisers and consumers but increases product prices, even without price‐discrimination. We provide conditions under which disclosure or privacy is privately and/or socially optimal. When advertisers compete on the downstream market, disclosure can lead to an increase or a decrease in product prices depending on the nature of the information.     

Competitive equilibrium hyperinflation under rational expectations

This paper shows that a competitive equilibrium model, where a representative agent maximizes welfare, expectations are rational and markets are in equilibrium can account for several hyperinflation stylized facts. The theory is built by combining two hypotheses, namely, a fiscal crisis that requires printing money to finance an increasing public deficit and a predicted change in an unsustainable fiscal regime.We thank an anonymous referee for very helpful comments. A. B. Cunha acknowledges financial support from the Brazilian Council of Science and Technology (CNPq).     

Spectral risk measures and portfolio selection

This paper deals with risk measurement and portfolio optimization under risk constraints. Firstly we give an overview of risk assessment from the viewpoint of risk theory, focusing on moment-based, distortion and spectral risk measures. We subsequently apply these ideas to an asset management framework using a database of hedge funds returns chosen for their non-Gaussian features. We deal with the problem of portfolio optimization under risk constraints and lead a comparative analysis of efficient portfolios. We show some robustness of optimal portfolios with respect to the choice of risk measure. Unsurprisingly, risk measures that emphasize large losses lead to slightly more diversified portfolios. However, risk measures that account primarily for worst case scenarios overweight funds with smaller tails which mitigates the relevance of diversification.     

The current account as a dynamic portfolio choice problem

The current account can be understood as the outcome of investment decisions made by domestic and foreign investors. These decisions can be decomposed into portfolio rebalancing and portfolio growth components, as highlighted by theoretical models. The empirical literature draws attention to the relative importance of portfolio rebalancing to explain fluctuations in capital flows, although they do not shed light on the mechanisms behind these rebalancing effects. In this paper, we provide empirical evidence of the importance of portfolio rebalancing driven by changes in investment opportunities for the dynamics of the current account. In particular, we evaluate the predictions of a partial-equilibrium model of the current account with dynamic portfolio choices, in which portfolio rebalancing is driven by changes in expected asset returns. Focusing on the dynamics of the current account between Japan and the US, we find evidence supporting innovations in investment opportunities as an important mechanism to explain international capital flows.