Reaching nirvana with a defaultable asset?

We study the optimal dynamic portfolio exposure to predictable default risk, taking inspiration from the search for yield by means of defaultable assets observed before the 2007–2008 crisis and in its aftermath. Under no arbitrage, default risk is compensated by an ‘yield pickup’ that can strongly attract aggressive investors via an investment-horizon effect in their optimal non-myopic portfolios. We show it by stating the optimal dynamic portfolio problem of Kim and Omberg (Rev Financ Stud 9:141–161, 1996) for a defaultable risky asset and by rigorously proving the existence of nirvana-type solutions. We achieve such a contribution to the portfolio optimization literature by means of a careful, closed-form-yielding adaptation to our defaultable asset setting of the general convex duality approach of Kramkov and Schachermayer (Ann Appl Probab 9(3):904–950, 1999; Ann Appl Probab 13(4):1504–1516, 2003).     

Minimax price bounds in incomplete markets

This paper develops an approach to tighten the bounds on asset prices in an incomplete market by combining no-arbitrage pricing and preference-based pricing, and the approach is applied to a call option in the absence of dynamic rebalancing. With the no-arbitrage pricing, it is straightforward to obtain the initial bounds, which are too wide to be of practical uses. By accepting that a representative agent exhibits risk aversion from a benchmark pricing kernel, it is possible to narrow the bounds considerably. Using the unbiased minimax deviation implicit in the parameters, one can restrict further the set of reasonable values on assets in incomplete markets.     

Working and Caring for a Child with Chronic Illness: Challenges in Maintaining Employment

This paper shares some pertinent findings from an initial, qualitative stage of a larger, national study currently being undertaken in Australia, exploring the support needs of parents who are working full time and caring for a child with chronic illness. The findings presented here depict the negative impact of these parents caring responsibilities on their work life and the increased stress they experience trying to maintain full time employment. In-depth interviews revealed how these parents had to rearrange their working hours, use up their leave entitlements, work unsatisfactory hours, sacrifice their careers and even change their jobs in order to balance their dual roles. In addition, the findings also highlight the negative and unsupportive attitude that employers had towards these parents. These employment conditions were extremely stressful and frustrating for parents affecting their physical and emotional well being.     

A Note on Clean Technology Adoption and its Influence on Tradeable Emission Permits Prices

In this paper, we give an example in which the price of tradable emission permits increases despite firms’ adoption of less polluting technology, a result that is in contrast with Montero (J Environ Econ 44:23–44, 2002) and Parry (J Regul Econ 14:229–254, 1998), among others. If two Cournot players switch to a cleaner technology, the price for permits may increase due to an increase in the net demand for permits and a decrease in the net supply of permits after the clean technology is adopted. This is only the case when output demand is quite elastic.     

Convex and convex-like optimization over a range inclusion problem and first applications

The paper deals with the minimization of a function over the solution set of a range inclusion problem determined by a multifunction. A strong Lagrange duality is provided first in terms of a quasirelative interior condition and then under a so-called Assumption (S). When the function and the multifunction are convex, we improve this duality under a closed cone condition. The stability analysis is investigated. In addition, if the multifunction is a convex process, then the Fenchel dual is performed in terms of its conjugate. As a first application, we provide a unified approach to the optimization of general discrete inclusions systems; in particular, we improve several results on optimal control, strong Lagrange duality and Fenchel duality for some classes of convex controlled discrete processes.     

The long-run performance of diversifying firms

The corporate diversification literature presents a puzzle. Short-horizon event studies report positive abnormal returns around the announcement of a diversifying event, while studies that examine diversified firms find evidence that diversified firms are worth less than specialized firms (a diversification discount). If diversification is value destroying, perhaps the destruction occurs over longer periods than have been previously tested. This paper tests the hypothesis that diversifying firms have negative long-run abnormal performance following diversification by examining a sample of specialized firms that have a diversifying event from 1978 through 1998. The firms are tracked for up to five years past their diversification year. There is evidence that value is destroyed for small firms that diversify but enhanced for larger firms that diversify.

Asymmetric information as a barrier to knowledge spillovers in expert markets

This paper investigates barriers to effective knowledge spillovers for markets in which the product can be characterized as a credence good, i.e. its complexity impedes the evaluation of quality by customers both ex-ante and ex-post. We focus on the German market for energy efficiency consultants, as an emerging and subsidized sector in which the service offered has strong credence good properties. Based upon in-depth interviews with stakeholders, we analyze the determinants and barriers to knowledge spillovers. We find that the incentive to foster spillovers to increase suppliers’ knowledge is limited by the difficult commercialization of additional capabilities. The implementation of a public certification scheme has failed to increase the sectoral knowledge spillovers. By contrast, the participation in formal knowledge networks has been more effective in prompting companies to foster knowledge spillovers, which has also led to a higher degree of specialization. We conclude that access to certification schemes should be further restricted to increase market transparency and private networks should be supported to achieve the aim of increasing knowledge spillovers.