Notes on Applying Real Options to Climate Change Adaptation Measures, with examples from Vietnam

A factor common to all adaptation measures is the uncertainty that is the hallmark of climate change. The timing, intensity and location of climate change impacts is not known to any degree of precision. Because most deterministic analyses and policy prescriptions ignore this uncertainty, their recommendations are likely to waste community resources. Except by chance, adaptation measures will either be over-engineered, or they will be inadequate and result in harm. Applying real options thinking allows an incremental and flexible approach. Adaptation measures are implemented only as better knowledge becomes available over time. Several examples are given of real options in the Mekong Delta, with a comparison of net present values of two housing alternatives. It is essential to undertake net present value calculations when comparing different projects to ensure that the value of any options is weighed against other costs and benefits.Environmental Economics and Policy,

Thermodynamic Analogy for Structural Phase Transitions

We investigate the relationship between ground-state (zero-temperature) quantum phase transitions in systems with variable Hamiltonian parameters and classical (temperature-driven) phase transitions in standard thermodynamics. An analogy is found between (i) phase-transitional distributions of the ground-state related branch points of quantum Hamiltonians in the complex parameter plane and (ii) distributions of zeros of classical partition functions in complex temperatures. Our approach properly describes the first- and second-order quantum phase transitions in the interacting boson model and can be generalized to finite temperatures.Comment: to be published by AIP in Proc. of the Workshop "Nuclei and Mesoscopic Physics" (Michigan State Univ., Oct 2004); 10 pages, 3 figure

Using Volterra Series for an Estimation of Fundamental Intermodulation Products

The most precise procedure for determining the intermodulation products is to find a steady-state period of the signal first, and then to calculate its spectrum by means of the fast Fourier transform. However, this method needs time-consuming numerical integration over many periods of the faster signal even for enhanced methods for finding the steady state. In the paper, an efficient method for fast estimation of the fundamental intermodulation products is presented. The method uses Volterra series in a simple multistep algorithm which is compatible with a typical structure of the frequency-domain part of circuit simulators. The method is demonstrated by an illustrative testing circuit first, which clearly shows possible incorrect interpretation of the Volterra series. Thereafter, practical usage of the algorithm is demonstrated by fast estimation of the main intermodulation products of a low-voltage low-power RF CMOS fourquadrant multiplier

Getting real about adapting to climate change: using 'real options' to address the uncertainties

Scientists predict that some climate change is already inevitable, even if greenhouse emissions are stabilised. Adaptation strategies will be of comparable importance to reducing emissions. However, the specific effects of climate change are currently unknowable, especially at the local level. Given this uncertainty, deterministic adaptation strategies are inappropriate. Rather than building ‘worst-case scenario’ sea walls, for example, strong foundations can be laid — so that walls can be built (or not built) in future to match actual climatic conditions without incurring unnecessary upfront expense. Other examples of such ‘real options’ are provided to illustrate the feasibility of the approach

Adaptor of last resort? An economic perspective on the government’s role in adaptation to climate change

Abstract Individuals and societies have always adapted to change, whether catastrophic or slow onset. Over the last two centuries, however, governments have significantly extended their role as ultimate social manager of risk.  It is as yet unclear whether, how, or to what extent governments will add adaptation to climate change to their portfolio of responsibilities.  This report investigates this question on the basis of review and analysis of economic and policy thinking on the issues, and by using a new dataset on the 2011 Brisbane flood. Uncertainties about the future impacts of climate change obviate definitive conclusions about future adaptation actions and insights for specific situations cannot be generalised.  Economic precepts suggest that governments should limit intervention to cases of genuine market failure, such as the provision of information on likely impacts of climate change including at the local level, or to support for people affected by uninsurable events.  But any role as ‘insurer of last resort’ needs to be circumscribed by rigorous social cost-benefit analysis to ensure that government intervention is beneficial, in the context of the need to adapt to climatic changes.  Although the phenomenon of ‘government failure’ is generally ignored in the adaptation literature (and often by policy makers), it too can stymie efficient adaptation.  A standard justification for government intervention is market failure, including misperception of risk by individuals and businesses.  We use Brisbane property prices before and after the January 2011 flood, as well as property-level flood risk information to test the hypothesis that buyers do not accurately perceive the risk of riverine flooding.  The results indicate that buyers do take risk into account, and even discriminate between zones of differing flood risk.  The concepts of ‘government as insurer of last resort’ and ‘government as insurer of first resort’ as alternative forms of intervention in markets are examined with a view to disambiguation.  In contrast to much current thinking in academic and government circles, we conclude that the government should not act as an ‘adaptor of first or last resort’.  Rather, government can best contribute to efficient adaptation by reducing the economic costs and institutional barriers to adaptation faced by individuals and organisations.Comprehensive micro-economic reform, and the promotion of institutional flexibility are potential ‘no regrets’ strategies because they will also promote economic growth and welfare.Please cite as: Dobes, L, Jotzo, F, Doupé, P 2013 Adaptor of last resort? An economic perspective on the Government’s role in adaptation to climate change, National Climate Change Adaptation Research Facility, Gold Coast, pp. 81.Individuals and societies have always adapted to change, whether catastrophic or slow onset. Over the last two centuries, however, governments have significantly extended their role as ultimate social manager of risk.  It is as yet unclear whether, how, or to what extent governments will add adaptation to climate change to their portfolio of responsibilities.  This report investigates this question on the basis of review and analysis of economic and policy thinking on the issues, and by using a new dataset on the 2011 Brisbane flood. Uncertainties about the future impacts of climate change obviate definitive conclusions about future adaptation actions and insights for specific situations cannot be generalised.  Economic precepts suggest that governments should limit intervention to cases of genuine market failure, such as the provision of information on likely impacts of climate change including at the local level, or to support for people affected by uninsurable events.  But any role as ‘insurer of last resort’ needs to be circumscribed by rigorous social cost-benefit analysis to ensure that government intervention is beneficial, in the context of the need to adapt to climatic changes.  Although the phenomenon of ‘government failure’ is generally ignored in the adaptation literature (and often by policy makers), it too can stymie efficient adaptation.  A standard justification for government intervention is market failure, including misperception of risk by individuals and businesses.  We use Brisbane property prices before and after the January 2011 flood, as well as property-level flood risk information to test the hypothesis that buyers do not accurately perceive the risk of riverine flooding.  The results indicate that buyers do take risk into account, and even discriminate between zones of differing flood risk.  The concepts of ‘government as insurer of last resort’ and ‘government as insurer of first resort’ as alternative forms of intervention in markets are examined with a view to disambiguation.  In contrast to much current thinking in academic and government circles, we conclude that the government should not act as an ‘adaptor of first or last resort’. Rather, government can best contribute to efficient adaptation by reducing the economic costs and institutional barriers to adaptation faced by individuals and organisations.Comprehensive micro-economic reform, and the promotion of institutional flexibility are potential ‘no regrets’ strategies because they will also promote economic growth and welfare.Please cite as: Dobes, L, Jotzo, F, Doupé, P 2013 Adaptor of last resort? An economic perspective on the Government’s role in adaptation to climate change, National Climate Change Adaptation Research Facility, Gold Coast, pp. 81.&nbsp

An Efficient Procedure for the Time-Domain Sensitivity Analysis

Standard tools for CAD have limited modes of the sensitivity analysis: PSPICE only contains a static mode and SPECTRE includes frequency-domain and static modes. However, many RF systems use symmetrical structures for enhancing the circuit properties. For such systems, the static sensitivities are zero on principle and hence the time-domain sensitivity analysis should be used. In the paper, a novel recurrent formula for the time/domain sensitivity analysis is derived which uses by-products of an efficient implicit integration algorithm. As the selected integration algorithm is more flexible than the Gear's one that is ordinary used, the sensitivity analysis is more efficient in comparison with the standard CAD tools. An implementation of the method is demonstrated using the analysis of a low-voltage four-quadrant RF multiplier. Nonstandard temperature sensitivity analyses are also tested in the static and dynamic modes

Treatment of the Progressive Endoleak Type 2 After EVAR

An endoleak type 2 (EL2) is a relatively frequent event after an EVAR but 30–35% of EL2 can become progressive, which can cause a loss in the important sealing zone of the stent graft. Diagnosis is made by three-phase CT angiogram or by contrast-enhanced duplex scan. EL2 should be treated if the aortic sac grows more than 5 mm in 6 months time. The first suitable treatment is the endovascular approach with embolization of the inferior mesenteric artery (IMA) or lumbar arteries. Paravertebral puncture, under CT navigation to embolize the lumbar artery or a part of the aortic sac with the EL2, is another alternative. If the endovascular treatment is not successful in 2–3 times, we should consider a surgical approach. The operative approach can be a laparoscopic or an open operation: the laparoscopic approach allows us to clip the IMA and lumbar arteries. The open surgery involves laparotomy, ligation of the IMA, and endoaneurysmorrhaphy (suture of lumbar artery origins from inside) and then the suture of the aortic sac tightly around the stent graft in situ. The aortic occlusion balloon should be inserted below the renal arteries prior to open surgery. The surgical procedures have good outcomes and should be considered when the endovascular treatment is unsuccessful

Temporal trends in incidence of primary brain tumours in the Australian Capital Territory and New South Wales 2000 to 2008

There are conflicting reports from Europe and North America regarding trends in the incidence of primary brain tumour, whereas the incidence of primary brain tumours in Australia is currently unknown. We aimed to determine primary brain tumour incidence in Australia with age-, sex-, and benign-versus-malignant histology-specific analyses. A multicenter study was performed in the state of New South Wales (NSW) and the Australian Capital Territory (ACT), representing a combined population of >7 million with >97% rate of population retention for medical care. We retrospectively sourced pathology databases servicing neurosurgical centres in NSW and ACT for histologically confirmed primary brain tumours diagnosed from January 2000 through December 2008. Data were weighted for patient outflow and data completeness. Incidence rates were age standardised and trends analysed using joinpoint analysis. A weighted total of 7651 primary brain tumours were analysed. The overall US-standardised incidence of primary brain tumours was 11.3 cases 100000 person-years (+0.13; 95% confidence interval, 9.8-12.3) during the study period with no significant linear increase. A significant increase in primary malignant brain tumours from 2000 to 2008 was observed; this appears to be largely due to an increase in malignant tumour incidence in the {u2265}65-year age group. A significant increasing incidence in glioblastoma multiforme (GBM) was observed in the study period (annual percentage change, 2.5; 95% confidence interval, 0.4-4.6, n=2275), particularly after 2006. In GBM patients in the {u2265}65-year group, significantly increasing incidence for men and women combined (APC, 3.0; 95% CI, 0.5-5.6) and men only (APC, 2.9; 95% CI, 0.1-5.8) were seen. Rising trends in incidence were also seen in meningioma for total male population (APC, 5.3; 95% CI, 2.6-8.1, n=515) and males aged 20-64 years (APC, 6.3; 95% CI, 3.8-8.8). Significantly decreasing incidence trends were observed for Schwannoma for the total study population (APC, -3.5; 95% CI, -7.2 - -0.2, n=492), significant in women (APC, -5.3; 95% CI, - 9.9 - -0.5) but not men. This collection represents the best estimate of primary brain tumour incidence in Australia. Whether the observed increase in malignant primary brain tumours, particularly in persons aged {u2265}65 years, is due to improved detection, diagnosis, and care delivery or a true change in incidence remains undetermined. An important trend observed from this study, using benign tumour data collection, was an increasing trend in meningioma and a decreasing trend in Schwannoma in the years 2000 to 2008. This is data for which we have no direct comparison in Australia. Our registries may observe an increase in malignant tumours in the next few years that they are not detecting now due to late ascertainment. We recommend a direct, uniform and centralized approach to monitoring primary brain tumour incidence, including the introduction of non-malignant tumour data collection

SDG fermion-pair algebraic SO(12) and Sp(10) models and their boson realizations

It is shown how the boson mapping formalism may be applied as a useful many-body tool to solve a fermion problem. This is done in the context of generalized Ginocchio models for which we introduce S-, D-, and G-pairs of fermions and subsequently construct the sdg-boson realizations of the generalized Dyson type. The constructed SO(12) and Sp(10) fermion models are solved beyond the explicit symmetry limits. Phase transitions to rotational structures are obtained, also in situations where there is no underlying SU(3) symmetry.Comment: 25 LaTeX pages, 4 uuencoded postscript figures included, Preprint IFT/8/94 & STPHY-TH/94-