Integrated Assessment of Climate Change Using an OLG Model

This paper presents an economy and climate model of 60 overlapping generations of finite lived agents and competitive firms interacting with a physical environment. Use of energy in production results in the release of carbon to the atmosphere which can affect global climate, and thus productivity. The model is calibrated to global economic activity over the 30 years ended in 1995. The model is solved using an Euler equation approach, and simulated for three climate change scenarios, capturing optimistic, median, and pessimistic predictions on the rate and severity of climate change in response to CO2 emissions.Climate Change, Environmental Taxes, Environmental Regulation.

The Climate Change Learning Curve

The key element in the tension between those who believe climate change is an issue and those who do not is essentially the question of whether we are merely in a long period of shock-induced above average temperatures or if we have led to this increase in temperatures by anthropogenic carbon emissions. The model proposed in this paper allows for a model in which we weigh observations on temperature against the potential that these are generated by a combination of uncertain parameters; namely the coefficient of autoregression and the sensitivity of temperature change to atmospheric carbon levels. This paper shows that, contrary to predictions in the literature that we can resolve uncertainty very quickly, the time to learn may be on the order of thousands of years when uncertainty surrounds two parameters in the law of motion for temperature. When the learning model is embedded in an optimal policy growth model, policy decisions are found to be affected by the prior mean but not the variance. A new solution algorithm which relies on randomization and least squares approximation is applied to solve the value function in the model.Climate Change; Bayesian Learning; Environmental Regulation; Growth; Pollution; Dynamic Programming; Precautionary Principle.

Microwave background constraints on inflationary parameters

We use a compilation of cosmic microwave anisotropy data (including the recent VSA, CBI and Archeops results), supplemented with an additional constraint on the expansion rate, to directly constrain the parameters of slow-roll inflation models. We find good agreement with other papers concerning the cosmological parameters, and display constraints on the power spectrum amplitude from inflation and the first two slow-roll parameters, finding in particular that $\epsilon_1 < 0.057$. The technique we use for parametrizing inflationary spectra may become essential once the data quality improves significantly.Comment: 6 pages LaTeX file with figures incorporated. Major revisions including incorporation of new datasets (CBI and Archeops). Slow-roll inflation module for use with the CAMB program can be found at http://astronomy.cpes.susx.ac.uk/~sleach/inflation

Energy Regulation in Quebec

This report characterizes the regulation of energy markets in general and focuses on the electricity and natural gas markets of Québec. Markets are regulated if they are deemed to represent natural monopoly situations or if unregulated firms would not take into account externalities that they might generate. Energy market regulation has been justified with the claim that regulation represents the “second-best” alternative. That is, given a situation in which there is market failure, the outcome derived under regulation may be better than the outcome that would arise if the market were unregulated. Government intervention may be required in order to protect the interests of consumers. Energy markets have been considered natural monopoly situations in large part because of the enormous fixed costs associated with production and distribution. Furthermore, electricity and natural gas are generally considered essential goods, or more accurately, goods with significant positive externalities from reliable supply. A reliable supply is necessary for the proper functioning of any modern economy and a private market might not provide equally for all people in a service area. In recent years, however, certain segments of some energy markets have been liberalized, since these segments might not actually be natural monopoly situations and/or because the market may provide means to ensure that firms internalize externalities. We describe the experiences of a number of jurisdictions that have experimented with energy market liberalization and show that restructuring is feasible and may provide an improvement over the status quo if market power can be limited. We consider the potential for restructuring in Québec’s energy markets which are currently mainly regulated by the Régie de l’énergie du Québec. Québec’s electricity market does not represent a typical case for the restructuring of the production side since the vast majority of its generating capacity comes from hydro projects. Over 90% of Québec’s installed electrical capacity is hydro generated, making Québec the second most hydro-dominated market in the world after Norway. Furthermore, this capacity is highly concentrated on three river systems. The usual model of forced divestiture by hydrologic system is therefore likely to introduce market power in a restructured market, and may lead to greater inefficiencies than those present under regulation. In order for any market restructuring to succeed, (at least) one of two approaches must be undertaken. A system of tradable water rights could be established in parallel with a competitive power pool in order to allow divestiture of individual plants within a river system and/or Québec’s markets could be opened to foreign production. The retail segment of Québec’s energy markets could potentially benefit from liberalization. The only obvious difference between Québec’s energy markets and those in other jurisdictions is Québec’s price-equalization policy. Lower prices could prevail if competition were introduced to the markets for electricity and natural gas, but not for all consumers. Québec’s insistence on uniform prices throughout the province means that some consumers are currently paying below market price for energy. Prices for these consumers could rise if the market is restructured.

Induced innovation in a decentralized model of climate change

We propose a model of climate change consistent with four principal stylized facts. First, the benefits and costs of climate change mitigation policies are not evenly distributed across generations. Second, capital accumulation is not determined jointly with emissions policy, but rather as a choice made by self-interested economic agents. Third, most research and development activity in the energy sector is undertaken by private firms. Fourth, significant imperfections exist in the market for technology. The model is calibrated to match global trends in GWP, energy production, and investment in research and development, and is used for the evaluation of policies including research and development subsidies and carbon taxes.Alternative energy sources; climate change; technological change; research and development; induced innovation.

The universal expression for the amplitude square in quantum electrodynamics

The universal expression for the amplitude square |u_f M u_i|^2 for any matrix of interaction M is derived. It has obvious covariant form. It allows the avoidance of calculation of products of the Dirac's matrices traces and allows easy calculation of cross-sections of any different processes with polarized and unpolarized particles.Comment: 4 page

Symmetrized importance samplers for stochastic differential equations

We study a class of importance sampling methods for stochastic differential equations (SDEs). A small-noise analysis is performed, and the results suggest that a simple symmetrization procedure can significantly improve the performance of our importance sampling schemes when the noise is not too large. We demonstrate that this is indeed the case for a number of linear and nonlinear examples. Potential applications, e.g., data assimilation, are discussed.Comment: Added brief discussion of Hamilton-Jacobi equation. Also made various minor corrections. To appear in Communciations in Applied Mathematics and Computational Scienc

Modern architecture in Wellington

This lecture considers the prehistory of the Architectural Centre (Wellington, New Zealand), revising the chronology of debates on modern architecture in New Zealand

The myth of the nation: Historiography of New Zealand architecture since 1907

This paper considers the relationship between the recent historiography (of the last quarter century) of “New Zealand architecture” and the historical notion of “New Zealand-ness” invoked in contemporary architecture. It argues that a more recent programmatic uptake of post-War discussions on national identity and regional specificity has fed the tendencies of practicing architects to defer to history in rhetorical defences of their work: the beach-side mansion as a contemporary expression of the 1950s bach; a formal modernism divorced from the social discourse adherent to the historical moment that it “restates”; and so on. The paper will consider instances in the historiography of New Zealand architecture where historians have compounded, consciously or accidentally, a problem that is systemic to the uses made by architects of historical knowledge (in the most general examples), identifying the difficulties of relying upon the tentative conclusions of an under-studied field in developing principles of contemporary architectural practice under the banners of New Zealand-ness, regionalism, or localism, or with reference to icons of New Zealand architectural history. At the heart of this paper is a reflection on historiographical responsibility in presenting knowledge of a national past to an audience that is eager to transform that knowledge into principles of contemporary production. What, the paper asks, is the historical basis for speaking of a New Zealand architecture? Can we speak of a national history of architecture distinct from a regional history, or from an international history of architecture