Benchmark Status in Fixed-Income Asset Markets

What is a benchmark bond? We provide a formal theoretical treatment of this concept that relates endogenously determined benchmark status to the location of price discovery and we derive its implications. We describe a rich but little used econometric technique for identifying the benchmark that is congruent with our theoretical framework. We apply this in the context of the US corporate bond market and to the natural experiment that occurred when benchmark status was contested in the European sovereign bond markets after the introduction of the Euro. We show that France provides the benchmark at most maturities in the Euro-denominated sovereign bond market and that IBM provides the benchmark in the 10 year maturity in the US corporate bond market.

Observation of Collisionless Shocks in Laser-Plasma Experiments

The propagation in a rarefied plasma (n(e)less than or similar to 10(15) cm(-3)) of collisionless shock waves and ion-acoustic solitons, excited following the interaction of a long (tau(L)similar to 470 ps) and intense (I similar to 10(15) W cm(-2)) laser pulse with solid targets, has been investigated via proton probing techniques. The shocks' structures and related electric field distributions were reconstructed with high spatial and temporal resolution. The experimental results were interpreted within the framework of the nonlinear wave description based on the Korteweg-de Vries-Burgers equation.

A framework for assessing the vulnerability of food systems to future shocks

Modem society depends on complex agro-ecological and trading systems to provide food for urban residents, yet there are few tools available to assess whether these systems are vulnerable to future disturbances. We propose a preliminary framework to assess the vulnerability of food systems to future shocks based on landscape ecology's 'Panarchy Framework'. According to Panarchy, ecosystem vulnerability is determined by three generic characteristics: (1) the wealth available in the system, (2) how connected the system is, and (3) how much diversity exists in the system. In this framework, wealthy, non-diverse, tightly connected systems are highly vulnerable. The wealth of food systems can be measured using the approach pioneered by development economists to assess how poverty affects food security. Diversity can be measured using the tools investors use to measure the diversity of investment portfolios to assess financial risk. The connectivity of a system can be evaluated with the tools chemists use to assess the pathways chemicals use to flow through the environment. This approach can lead to better tools for creating policy designed to reduce vulnerability, and can help urban or regional planners identify where food systems are vulnerable to shocks and disturbances that may occur in the future. (c) 2005 Elsevier Ltd. All rights reserved.

SiO in G34.26: Outflows and shocks in a high mass star forming region

We have looked for SiO emission as evidence of shocks in the high mass star formation region G34.26+0.15. JCMT, VLA and FCRAO observations show that SiO emission is widespread across the region. The SiO emission highlights a massive, collimated out ow and other regions where stellar winds are interacting with molecular clumps. As in other star forming regions, there is also SiO at ambient velocities which is related to the out ow activity. No strong SiO abundance enhancement was measured in either the out ow or the low velocity gas, though abundances up to 10(-8) are possible if the SiO is locally enhanced in clumps and optically thick. SiO emission is not detected from the hot core itself, indicating either that SiO is not strongly enhanced in the hot core or that column densities in the region where grain mantle evaporation has taken place are low. In line of sight spiral arm clouds, we measure a SiO abundance of 0.4-2 x 10(-10), consistent with previous estimates for quiescent clouds.

Managing time: integration of care and paid work amongst low income families and the role of the United Kingdom’s tax credit system

Under the New Labour Governments in the UK, successive reforms of the tax and benefit system sought to improve the financial benefits of paid work. Drawing on two waves of qualitative interviews with low-income working families this article examines the role of the UK tax credit system in shaping decisions about employment and unpaid care work. The article suggests that the financial support provided for lone parent participants by the tax credit system enhanced their temporal autonomy, permitting participation in paid work to align more closely with temporally situated notions of parental responsibility for caring. For couple families however, parental perceptions of responsibility for pre-school children, along with childcare constraints and the structure of the tax credit system served to constrain the autonomy of the main carer and implicitly encourage a gendered specialisation in caring or employment.

Discretization of highly persistent correlated AR(1) shocks

The finite state Markov-chain approximation methods developed by Tauchen (1986) and Tauchen and Hussey (1991) are widely used in economics, finance and econometrics to solve functional equations in which state variables follow autoregressive processes. For highly persistent processes, the methods require a large number of discrete values for the state variables to produce close approximations which leads to an undesirable reduction in computational speed, especially in a multivariate case. This paper proposes an alternative method of discretizing multivariate autoregressive processes. This method can be treated as an extension of Rouwenhorst's (1995) method which, according to our finding, outperforms the existing methods in the scalar case for highly persistent processes. The new method works well as an approximation that is much more robust to the number of discrete values for a wide range of the parameter space.

High pressures generated by laser driven shocks: applications to planetary physics

High power lasers are a tool that can be used to determine important parameters in the context of Warm Dense Matter, i.e. at the convergence of low-temperature plasma physics and finite-temperature condensed matter physics. Recent results concerning planet inner core materials such as water and iron are presented. We determined the equation of state, temperature and index of refraction of water for pressures up to 7 Mbar. The release state of iron in a LiF window allowed us to investigate the melting temperature near the inner core boundary conditions. Finally, the first application of proton radiography to the study of shocked material is also discussed.

Ascending Out of Poverty: An analysis of family histories in Kenya

This paper looks at inheritance through minimally-structured interviews with several generations of Kenyan families, seeking to explain that the how and why of poverty can be understood in the wider family context. Five main routes for ascending out of poverty were identified: (1) the gradual accumulation of resources due to income deriving from cash crops; (2) the gradual accumulation of resources due to income from non-farm work, including remittances from family member who have moved away for work; (3) the role of education, particularly skills training opposed to academic qualification, in helping provide employment; (4) accessing financial assets through support both from extended family members and from informal support mechanisms; (5) stability and benefits accruing from long-term strategic planning, including entrepreneurial activity. Both the ascent out of and the descent into poverty can be better conceived as processes, rather than due to chains of discrete events or specific ‘shocks’.