bluuebunny/crossref_metadata_2025 huggingface dataset:
A Simple Note on Informational Cascades
Authors: Fiore Annamaria , Morone Andrea
Published: September 2010

Seminal models of herd behaviour and informational cascades point out existence of negative information externalities, and propose to ‘destroy’ information in order to achieve social improvements. Although in the last years many features of herd behaviour and informational cascades have been studied, this particular aspect has never been extensively analysed. In this article we try to fill this gap, investigating both theoretically and experimentally whether and to which extent destroying information can improve welfare. Our empirical results show that this decisional mechanism actually leads to a behaviour pattern more consistent with the theory that in turn produces the predicted efficiency gain.
Measuring Real Value and Inflation
Authors: Hillinger Claude
Published: September 2010

The most important economic measures are monetary. They have many different names, are derived in different theories and employ different formulas; yet, they all attempt to do the same thing: to separate a change in nominal value into a ‘real part’ due to the changes in quantities and an inflation due to the changes in prices. Examples are: real national product and its components, the GNP deflator, the CPI, various measures related to consumer surplus, as well as the large number of formulas for price and quantity indexes that have been proposed. The theories that have been developed to derive these measures are largely unsatisfactory. The axiomatic theory of indexes does not make clear which economic problem a particular formula can be used to solve. The economic theories are for the most part based on unrealistic assumptions. For example, the theory of the CPI is usually developed for a single consumer with homothetic preferences and then applied to a large aggregate of diverse consumers with non-homothetic preferences.

In this paper I review both the general literature and my own past contributions in order to identify theories of measurement that are based on plausible economic assumptions. It turns out that all such theories lead to the Törnqvist price or quantity indexes. The paper also covers several related topics, particularly the presently unsatisfactory determination of the components of real GDP. I also propose a novel set of integrated accounts to measure changes in relative prices as well as the sectoral sources of inflation.
Global Factors, Unemployment Adjustment and the Natural Rate
Authors: Smith Ron , Zoega Gylfi
Published: September 2010

OECD unemployment rates show long swings which dominate shorter business cycle components and these long swings show a range of common patterns. Using a panel of 21 OECD countries 1960-2002, we estimate the common factor that drives unemployment by the first principal component. This factor has a natural interpretation as a measure of global expected returns, which is given added plausibility by the fact that it is almost identical to the common factor driving investment shares. We estimate a model of unemployment adjustment, which allows for the influence both of the global factor and of labour market institutions and we examine whether the global factor can act as a proxy for the natural rate in a Phillips Curve. In 15 out of the 21 countries one cannot reject that the same natural rate, as a function of the global factor, appears in both the unemployment and inflation equations. In explaining both unemployment and inflation, the global factor is highly significant, suggesting that models which ignore the global dimension are likely to be deficient.
The New Keynesian Phillips Curve Tested on OECD Panel Data
Authors: Bjørnstad Roger , Nymoen Ragnar
Published: September 2010

Using a panel data set for OECD countries we replicate the typical features of the New Keynesian Phillips curve models (NPCs) that have been estimated on country data. While this corroborates the NPC also on the macro panel data set, a different conclusion is reached when we test whether the NPC encompasses an existing model of inflation which is without feed-forward terms, but which allows for other adjustment factors than the NPC. We find that the NPC’s expected rate of future inflation and real marginal costs are weak explanatory variables, and that their statistical significance in the typical NPC is due to correlation with the equilibrium correction terms that are implied by the existing inflation model. Our results are in line with the relatively few encompassing studies that exist on country and area data.
The Social Cost of Carbon: Trends, Outliers and Catastrophes
Authors: Tol Richard S.J.
Published: September 2010

211 estimates of the social cost of carbon are included in a meta-analysis. The results confirm that a lower discount rate implies a higher estimate; and that higher estimates are found in the gray literature. It is also found that there is a downward trend in the economic impact estimates of the climate; that the Stern Review’s estimates of the social cost of carbon is an outlier; and that the right tail of the distribution is fat. There is a fair chance that the annual climate liability exceeds the annual income of many people.
West-East Convergence in the Prevalence of Cannabis Use: Socioeconomics or Culture?
Authors: Tauchmann Harald
Published: September 2010

In contrast to West Germany, illicit drugs were virtually absent in East Germany until 1990. However, after the collapse of the former GDR, East Germany was expected to encounter a sharp increase in substance abuse. By analyzing individual data, we find that East Germany largely caught up with West Germany’s ever-growing prevalence of cannabis use within a single decade. We decompose the west-east difference in prevalence rates into an explained and an unexplained part using a modified Blinder-Oaxaca procedure. This decomposition suggests that the observed convergence is only weakly related to socioeconomic characteristics and therefore remains mainly unexplained. That is, West and East Germans seem to have become more alike per se. We conclude that both parts of the country have converged in terms of the culture of cannabis consumption.
Evaluating the New Keynesian Phillips Curve under VAR-based Learning
Authors: Fanelli Luca
Published: September 2010

This paper proposes an econometric evaluation of the New Keynesian Phillips Curve (NKPC) in the euro area, under a particular specification of the adaptive learning hypothesis. The key assumption is that agents’ perceived law of motion is a Vector Autoregressive (VAR) model, whose coefficients are updated by maximum likelihood estimation as the information set increases over time. Each time new data is available, likelihood ratio tests for the cross-equation restrictions that the NKPC imposes on the VAR coefficients are computed and compared with a proper set of critical values, which take the sequential nature of the test into account. The analysis focuses on the case in which the variables can be approximated as nonstationary cointegrated processes. Results on quarterly data relative to the period 1981−2006 show that: (i) the euro area inflation rate and the wage share are cointegrated, although their relationship does not appear stable during the eighties and first nineties; (ii) the cointegrated version of the ‘hybrid’ NKPC is sharply rejected under the rational expectations hypothesis; (iii) the NKPC is rejected also when the model is evaluated under a particular formulation of the adaptive learning hypothesis over the monitoring period 1986−2006.
Should We Trust the Empirical Evidence from Present Value Models of the Current Account?
Authors: Mercereau Benoît , Miniane Jacques
Published: September 2010

The present value model of the current account has been very popular, as it provides an optimal benchmark to which actual current account series have often been compared. We show why persistence in observed current account data makes the estimated optimal series very sensitive to small-sample estimation error, making it almost impossible to determine whether the consumption-smoothing current account tracks the actual current account closely, or not closely at all. Moreover, the standard Wald test of the model will falsely accept or reject the model with substantial probability. Monte Carlo simulations and estimations using annual and quarterly data from five OECD countries strongly support our predictions. In particular, we conclude that two important consensus results in the literature – that the optimal series is highly correlated with the actual series, but substantially less volatile – are not statistically robust.
Measuring Long-Run Exchange Rate Pass-Through
Authors: de Bandt Olivier , Banerjee Anindya , Koźluk Tomasz
Published: September 2010

The paper discusses the issue of estimating short- and long-run exchange rate pass-through to import prices in euro area countries and reviews some problems with the measures recently proposed in the literature. Theoretical considerations suggest a cointegrating relationship (between import unit values, the exchange rate and foreign prices), which is typically ignored in existing empirical studies. We use time series and up-to-date panel data techniques to test for cointegration with the possibility of structural breaks and show how the long run may be restored in the estimation. The main finding is that allowing for possible breaks around the formation of EMU and the appreciation of the euro starting in 2001 helps restore a long run cointegration relationship, where over the sample period the fixed component of the pass-through decreased while the variable component tended to increase.
A Model of an Optimum Currency Area
Authors: Ricci Luca Antonio
Published: September 2010

This paper develops a model of the circumstances under which it is beneficial to participate in a currency area. The proposed two-country monetary model of trade with nominal rigidities encompasses the real and monetary arguments suggested by the optimum currency area literature: correlation of real and monetary shocks, international factor mobility, fiscal adjustment, openness, difference in national inflationary biases, and transactions costs. The effect of openness on the net benefits is ambiguous, contrary to the usual argument that more open economies are better candidates for a currency area. Also, prospective member countries do not necessarily agree on whether a given currency union should be created.
Now or Never: Environmental Protection under Hyperbolic Discounting
Authors: Winkler Ralph
Published: September 2010

The author analyzes the optimal investment in environmental protection in a model of non-overlapping hyperbolically discounting agents. He shows that, in the long run and in the absence of a commitment device, society is stuck in a situation where all agents prefer further investments, yet no agent invests. This holds no matter whether agents are aware of the time inconsistency of their preferences. As a consequence, awareness of the time-inconsistency problem poses at best a short run remedy. Moreover, such an outcome may be Pareto inefficient and may explain the weak performance of long-run environmental policies.
Macroeconomic Relaxation: Adjustment Processes of Hierarchical Economic Structures
Authors: Hawkins Raymond J. , Aoki Masanao
Published: September 2010

We show how time-dependent macroeconomic response follows from microeconomic dynamics using linear response theory and a time-correlation formalism. This theory provides a straightforward approach to time-dependent macroeconomic model construction that preserves the heterogeneity and complex dynamics of microeconomic agents. We illustrate this approach by examining the relationship between output and demand as mediated by changes in unemployment, or Okun’s law. We also demonstrate that time dependence implies overshooting and how this formalism leads to a natural definition of economic friction.
Should we Discount the Far-Distant Future at ist Lowest Possible Rate?
Authors: Gollier Christian
Published: September 2010

In this paper, we elaborate on an idea initially developed by Weitzman (1998) that justifies taking the lowest possible discount rate for far-distant future cash flows. His argument relies on the arbitrary assumption that when the future rate of return of capital (RRC) is uncertain, one should invest in any project with a positive expected net present value. We examine an economy with a risk-averse representative agent facing an uncertain evolution of the RRC. In this context, we characterize the socially efficient stochastic consumption path, which allows us in turn to use the Ramsey rule to characterize the term structure of socially efficient discount rates. We show that Weitzman’s claim is qualitatively correct if shocks on the RRC are persistent. On the contrary, in the absence of any serial correlation in the RRC, the term structure of discount rates should be flat.
On the Relation between Discounting of Climate Change and Edgeworth-Pareto Substitutability
Authors: Kögel Tomas
Published: September 2010

To justify substantial carbon emission reductions, recent literature on cost-benefit analysis of climate change suggests discounting environmental quality at a lower discount rate than the standard consumption discount rate. Recent literature also shows that a theoretical foundation for such a lower environmental discount rate requires rising willingness-to-pay for environmental quality (WTP). A widely believed better alternative is however to adjust instead future environmental benefits for rising WTP and to discount those benefits at the consumption discount rate. According to this latter approach, rising WTP is usually assumed not to change the consumption discount rate itself. Assuming environmental resource scarcity, the present paper shows that an unchanged consumption discount rate is however, by and large, only an appropriate assumption in the knife-edge case in which environmental quality and goods consumption are neither substitutes nor complements in the Edgeworth-Pareto sense (substitutes, respectively, complements in the Edgeworth-Pareto sense implies the marginal utility of goods consumption to be decreasing, respectively, increasing in environmental quality).
Inventory Investment and the Real Interest Rate
Authors: Junayed Sadaquat , Khan Hashmat
Published: September 2010

The relationship between inventory investment and the real interest rate has been difficult to assess empirically. Recent work has proposed a linear-quadratic inventory model with time-varying discount factor to identify the effects of the real interest rate on inventory investment. The authors show that this framework does not separately identify the effects of real interest rate on inventory investment from variables that determine the expected marginal cost of production. In other words, the model does not deliver a testable restriction on the impact of interest rates on inventory investment. The authors highlight the consequences for both short- and long-run empirical analyses. They conclude that understanding the relationship between inventory investment and the real interest rate continues to be a theoretical and empirical challenge for macroeconomists.
The Nature of Equilibrium in Macroeconomics: A Critique of Equilibrium Search Theory
Authors: Aoki Masanao , Yoshikawa Hiroshi
Published: September 2010

The standard Walrasian equilibrium theory requires that the marginal value product of production factor such as labor is equal across firms and industries. However, productivity dispersion is widely observed in the real economy. Search theory allegedly fills this gap by encompassing apparent disequilibrium phenomena in the neoclassical equilibrium framework. Taking up Lucas and Prescott (1974) as a primary example, we show that the neoclassical search theory cannot explain the observed pattern of productivity dispersion. Non-self-averaging, a concept little known to economists, plays the major role. Empirical observation suggests strongly the presence of disturbing forces which dominate equilibrating forces due to optimizing behavior of economic agents. We must seek a new concept of equilibrium different from the standard Walrasian equilibrium in macroeconomics.
The Information Content and Redistribution Effects of State and Municipal Rating Changes in Mexico
Authors: Velázquez Alfonso Mendoza
Published: September 2010

The fiscal and financial reforms carried out in Mexico in 2000 have encouraged a widespread presence of rating agencies and have allowed several States and Municipalities to raise funds through bond offerings in the capital market. Any local government in Mexico intending to access credit and capital markets must count with at least one credit rating from one of the three main agencies: FitchRatings, Moody’s and Standard & Poor’s. This paper investigates the impact of rating changes to State and Municipal governments on bond returns in Mexico. By employing a Capital Asset Pricing Model (CAPM) structure for the mean equation that allows conditional volatility, we find strong support for the Information Content Signaling Hypothesis (ICSH), i.e., rating upgrades (downgrades) are followed by greater (lower) bond returns. We also find some support for the Wealth Redistribution Hypothesis (WRH) indicating that rating upgrades (downgrades) are followed by lower (greater) bond returns. In addition to this, we find high volatility persistence, significant asymmetric responses of volatility to bad and good news, a negative association between market volatility and the level of bond returns and significant effects of volatility in response to rating changes. Finally, the estimations show the market anticipates and responds to rating changes within five-day momentum windows. There is a comparatively stronger reaction of returns on the event day favoring the hypothesis of market inefficiency.
Additive Damages, Fat-Tailed Climate Dynamics, and Uncertain Discounting
Authors: Weitzman Martin L.
Published: September 2010

This paper in applied theory argues that there is a loose chain of reasoning connecting the following three basic links in the economics of climate change: 1) additive disutility damages may be appropriate for analyzing some impacts of global warming; 2) an uncertain feedback-forcing coefficient, which might be near one with infinitesimal probability, can cause the distribution of the future time trajectory of global temperatures to have fat tails and a high variance; 3) when high-variance additive damages are discounted at an uncertain rate of pure time preference, which might be near zero with infinitesimal probability, it can make expected present discounted disutility very large. Some possible implications for welfare analysis and climate-change policy are briefly noted.
Addressing the Psychology of Financial Markets
Authors: Tuckett David
Published: September 2010

The author suggests that the 2008 financial crisis was the culmination of an accelerating and inherently unstable process of financial market evolution. He argues that markets are not well organized to manage the power that financial assets have to generate emotion and their wider effect on human imagination and judgement, anchored in neurobiology. Judgements and decisions about risk, reward and the evaluation of success can become systematically compromised because the excitement of potential gain is disconnected from anxiety about potential consequences, producing groupthink and bubbles. When anxiety breaks through, a catastrophic loss of confidence is inevitable. In the aftermath the emotional pain that would be involved in accepting responsibility stands in the way of lessons being learned.

The author’s theoretical framework is influenced by modern psychoanalysis and draws on an interview study of international fund managers in 2007. He suggests that underlying psychological conflicts have influenced the way market institutions have evolved to compete by selling the promise of exceptional performance. To cope with the expectations upon them, agents are impelled to base their actions on stories which overvalue opportunities and underestimate risks; this creates agency issues and facilitates the process of disconnecting anxiety from excitement that creates bubble potential. Policy implications go well beyond improving regulation and transparency.

Special issue

Managing Financial Instability in Capitalist Economies
Rethinking Global Climate Change Governance
Authors: Barrett Scott
Published: September 2010

This paper explains why the approach taken so far to mitigate global climate change has failed. The central reason is an inability to enforce targets and timetables. Current proposals recommending even stricter emission limits will not help unless they are able to address the enforcement deficit. Trade restrictions are one means for doing so, but trade restrictions pose new problems, particularly if they are applied to enforce economy-wide emission limitation agreements. This paper sketches a different approach that unpacks the climate problem, addressing different gases and sectors using different instruments. It also explains how a failure to address the climate problem fundamentally will only create incentives for different kinds of responses, posing different challenges for climate change governance.

Special issue “Global Governance—Challenges and Proposals for Reform” Published as Policy Paper
Global Governance of Global Monetary Relations: Rationale and Feasibility
Authors: Frieden Jeffry A.
Published: September 2010

Is there a valid argument for international cooperation, and some form of international governance structure, in the international monetary realm? On the purely economic front, the argument is not strong. Yet a broader political economy approach concludes that national currency policy can in fact impose non-pecuniary externalities on partner nations. This is especially the case with major policy-driven misalignments, which cannot easily be countered by other governments. For example, one country’s substantially depreciated currency can provoke powerful protectionist pressures in its trading partners, so that exchange rate policy spills over into trade policy in potentially damaging ways. Inasmuch as one government’s policies create these sorts of costs for other countries, and for the world economy as a whole, there is a case for global governance. This might include some institutionalized mechanism to monitor and publicize substantial currency misalignments. While there appears to be little global political attention to such a mechanism now, there have been initiatives along these lines at the regional level, and the current crisis may have stimulated more general stirrings of interest.

Special issue “Global Governance—Challenges and Proposals for Reform”

Published as Policy Paper
Forecast Evaluation of Explanatory Models of Financial Variability
Authors: Sucarrat Genaro
Published: September 2010

A practice that has become widespread and widely endorsed is that of evaluating forecasts of financial variability obtained from discrete time models by comparing them with high-frequencyex postestimates (e.g. realised volatility) based on continuous time theory. In explanatory financial variability modelling this raises several methodological and practical issues, which suggests an alternative approach is needed. The contribution of this study is twofold. First, the finite sample properties of operational and practical procedures for the forecast evaluation of explanatory discrete time models of financial variability are studied. Second, based on the simulation results a simple but general framework is proposed and illustrated. The illustration provides an example of where an explanatory model outperforms realised volatilityex post.
The Effect of Technological Innovation on International Trade
Authors: Márquez-Ramos Laura , Martínez-Zarzoso Inmaculada
Published: September 2010

In this paper, the effect of technological innovation on sectoral exports is analysed using a gravity model of trade. The technological achievement index (TAI) and its four components, creation of technology, diffusion of old innovations, diffusion of recent innovations and human skills, are used as proxies for technological innovation. The two first components are considered proxies for knowledge acquisition and assimilation (potential absorptive capacity), whereas the last two are taken as proxies for knowledge transformation and exploitation (realised absorptive capacity). We hypothesise that the effect of technological innovation on trade could vary according to the technological achievement by generating a non-linear relationship between technological innovation and trade. Our findings indicate a positive and non-linear effect of technological innovation on export performance, which indicates that there are thresholds for positive signs to occur. To foster exports, countries have to consider not only acquisition and assimilation capabilities, but also transformation and exploitation capabilities once a minimum level of potential absorptive capacity has been achieved.
Yes, We Should Discount the Far-Distant Future at Its Lowest Possible Rate: A Resolution of the Weitzman–Gollier Puzzle
Authors: Freeman Mark C.
Published: September 2010

In this paper the author proves that the Expected Net Future Value (ENFV) criterion can lead a risk neutral social planner to reject projects that increase expected utility. By contrast, the Expected Net Present Value (ENPV) rule correctly identifies the economic value of the project. While the ENFV increases with uncertainty over future interest rates, the expected utility decreases because of the planner’s desire to smooth consumption across time. This paper therefore shows that Weitzman (1998) is “right” and that, within his economy, the far-distant future should be discounted at its lowest possible rate.
Contribution of Health to Economic Development: A Survey and Overview
Authors: Husain Muhammad Jami
Published: September 2010

The policies for better health, poverty reduction, and less inequality, throughout the world, require thorough understanding of both the processes and causal paths that underlie the intricate relationship between health and wealth (income). This is deemed difficult, contingent, and only partially understood. The adage ‘health is wealth’ is still, primarily, an intuitive proposition. A vast majority of researchers instead present theoretical and empirical arguments of the reverse proposition, i.e. ‘wealth is health’. A recent strand of the literature, however, reflects changes in the perceptions: improvements of health and longevity are no longer viewed as a mere end- or by-product of economic development; but argued as one of the key determinants of, and therefore means to achieve, economic development and poverty reduction. Hence, better health does not have to wait for an improved economy; rather, measures to reduce the burden of disease, to give children healthy childhoods, to increase life expectancy etc. will in themselves contribute to creating richer economies. Drawing on the traditional and emerging perspectives on the health-income relationship, this literature review presents a non-exhaustive survey of existing methodological approaches and their results that are applied to track and measure how health influences economic outcomes.
Minimum Quality Standards and Novelty Requirements in a One-Short Development Race
Authors: Prokop Jacek , Regibeau Pierre , Rockett Katharine
Published: September 2010

We examine the timing and quality of product introduction in an R&D stopping game, where we allow for horizontal and vertical differentiation in the product market. We observe that discontinuous changes in introduction dates can occur as firms’ abilities as researchers change. Further, when the research abilities of the firms differ, either the high ability firm or the low ability firm may be the first mover. The underlying research abilities of the firms determine the social optimality of the entry patterns we observe. Minimum quality standards and novelty requirements can play a role in correcting these suboptimal patterns of entry. While minimum quality standards increase welfare for a large range of research abilities, we find that increasing the novelty requirement does not necessarily increase either the profits or, consequently, the research investment incentives of the initial innovator, contrary to much of the cumulative innovation literature. Indeed, as the effect of policy interventions differs significantly across industries where quality improvement is steep and those where it is flat, targeted policies towards specific industries as are often observed in minimum quality standards are generally preferable to more broad-based policies.
Investigating the Exponential Age Distribution of Firms
Authors: Coad Alex
Published: September 2010

While several plots of the aggregate age distribution suggest that firm age is exponentially distributed, we find some departures from the exponential benchmark. At the lower tail, we find that very young establishments are more numerous than expected, but they face high exit hazards. At the upper tail, the oldest firms are older than the exponential would have predicted. Furthermore, the age distribution of disaggregated industries (such as the international airline industry) is less regular and can display multimodality. Although we focused on departures from the exponential, we found that the exponential was a useful reference point and endorse it as an appropriate benchmark for future work on industrial structure.
The Great Recession vs. the Great Depression: Stylized Facts on Siblings That Were Given Different Foster Parents
Authors: Aiginger Karl
Published: September 2010

This paper compares the depth of the recent crisis and the Great Depression. We use a new data set to compare the drop in activity in the industrialized countries for seven activity indicators. This is done under the assumption that the recent crisis leveled off in mid-2009 for production and will do so for unemployment in 2010. Our data indicate that the recent crisis indeed had the potential to be another Great Depression, as shown by the speed and simultaneity of the decline in the first nine months. However, if we assume that a large second dip can be avoided, the drop in all indicators will have been smaller than during the Great Depression. This holds true specifically for GDP, employment and prices, and least for manufacturing output. The difference in the depth in the crises concurs with differences in policy reaction. This time monetary policy and fiscal policy were applied courageously, speedily and partly internationally coordinated. During the Great Depression for several years fiscal policy tried to stabilize budgets instead of aggregate demand, and either monetary policy was not applied or was rather ineffective insofar as deflation turned lower nominal interest rates into higher real rates. Only future research will be able to prove the exact impact of economic policy, but the current tentative conclusion is that economic policy prevented the recent crisis from developing into a second Great Depression. This is also a partial vindication for economists. The majority of them might not have been able to predict the crisis, but the science did learn its lesson from the Great Depression and was able to give decent policy advice to at least limit the depth of the recent crisis.
News versus Sunspot Shocks in a New Keynesian Model
Authors: Karnizova Lilia
Published: September 2010

Separately, news and sunspot shocks have been shown empirically to be determinants of changes in expectations. This paper considers both of them together in a simple New Keynesian monetary business cycle model. A full set of rational expectations solutions is derived analytically. The analytical characterization allows an explicit comparison of news about future monetary policy and sunspots. The key distinction between the shocks lies in their relation to the realized policy shock. If monetary policy is “passive”, both types of shocks affect model dynamics through forecast errors. The effect of the news on forecast errors is not unique, and the dynamics induced by news and sunspot shocks can be observationally equivalent. If monetary policy is “active”, the sunspots are irrelevant, and the model responses to the news shocks are unique. In both cases, news shocks strengthen the endogenous propagation of the model, since anticipation of future changes prolongs agents’ reaction. Keywords: news shocks, sunspots, expectations, monetary policy, indeterminacy.
Stabilizing an Unstable Economy: On the Choice of Proper Policy Measures
Authors: Asada Toichiro , Chiarella Carl , Flaschel Peter , Mouakil Tarik , Proaño Christian R.
Published: September 2010

In the last months, the world’s economies were confronted with the largest economic recession since the Great Depression. The occurrence of a worldwide financial market meltdown as a consequence originally stemming from of the crisis in the US subprime housing sector was only prevented by extraordinary monetary and fiscal policy measures implemented at the international level. Although the world economy seems now to be slowing recovering, it is worthwhile exploring the fragility and potentially destabilizing feedbacks of advanced macroeconomies in the context of Keynesian macro models. Fragilities and destabilizing feedback mechanisms are known to be potential features of all markets—the product markets, the labor market, and the financial markets. In this paper we focus in particular on the financial market. We use a Tobin-like macroeconomic portfolio approach, and the interaction of heterogeneous agents on the financial market to characterize the potential instability of the financial markets. Though the study of the latter has been undertaken in many partial models, we focus here on the interconnectedness of all three markets. Furthermore, we also study how labor market, fiscal and monetary policies can stabilize unstable macroeconomies. Besides other stabilizing policies we in particular propose a countercyclical monetary policy that sells assets in the boom and purchases assets in recessions. Modern stability analysis is brought to bear to demonstrate the stabilizing effects of those suggested policies.
The Multilateral Donor Non-System: Towards Accountability and Efficient Role Assignment
Authors: Reisen Helmut
Published: September 2010

Global governance refers to several pillars; one important pillar is the multilateral aid architecture. Its reform can be discussed under the perspectives of representativeness, inclusiveness, and efficiency (of aid delivery). A prerequisite for efficient aid delivery is to map the rising complexity of multilateral development finance, to help identify areas for consolidation, address fragmentation and poor co-ordination at country level, and help identify comparative advantages for an institutional role assignment among multilateral agencies. After doing just that, the paper explores why the multilateral donors have proliferated and provides broad recommendations for a more efficient and accountable multilateral donor system.
Influence of Fish Capture Methods on Genotoxic Assessment in Different Tissues of Astyanax fasciatus (Osteichthyes, Characidae)
Authors: Moreira T. N. , Nunes E. A. , Leal M. E. , Schulz U. H. , Lemos C. T. de
Published: September 2010

Among the approaches to evaluate genotoxicity of aquatic environments, fish are being used as biomonitors due to their sensitivity to any changes in the environment, characterizing it as sentinel organisms for the biomonitoring of rivers and lakes. Biomarkers that reflect damage to genetic material of fish are detected by the Comet Assay (EC) and through analysis of Micronucleus (MN) produced by different chemical agents and/or stressor factors due to capture, handling and keeping. Cast net and electric fishing were used for capture in this study, aiming to evaluate the influence of these methods on the analyzed biomarkers in different tissues, such as blood, gills and liver. Astyanax fasciatus (Characidae) individuals were captured in Quadros lagoon – RS, Brazil, site considered free on industrial contamination, showing a good physico-chemical quality. Results of MN test, which reflect clastogenic and aneugenic effects, presented no significant difference between the catch methods used, possibly because there was not enough time for cell division that is necessary for micronucleus forming. EC, which detects direct DNA brakeage, showed significant differences in Damage Index (ID) and Damage Percentage (%D) between capture methods in all tissues examined (p ≤ 0.001), indicating an effect of electricity on organisms collected.
Influence of Sacarose and Sodium Chloride in the Toxicity Evaluation of Environmental Samples Using V. Fischeri
Authors: Umbuzeiro G. A. , Hachich E. M. , Magri E. V. F. , Takeda S. H. K. , Sato M. I. Z.
Published: September 2010

The acute toxicity assay using the marine bacteria Vibrio fischeri requires osmotic adjustment for testing samples with low salt content. Two kinds of compounds can be used for this purpose, sodium chloride (NaCl) or sucrose. It is known that this osmotic adjustment can cause changes in the toxicity for some substances like some metals and ammonia. The toxicity of 29 environmental samples that included raw waters, industrial effluents, sediments, solid wastes and foams deriving from polluted water bodies was evaluated using NaCl and sucrose, in parallel. The two methods of osmotic adjustment showed a good agreement in terms of the qualitative responses for all samples analyzed. Only for five samples, the CE50 values were lower in sucrose than in NaCl, in agreement with the results of zinc and ammonia. The results obtained for the environmental samples tested with both methods suggest that NaCl can be used routinely. Additional analysis with sucrose can be especially helpful when metals like zinc and ammonia are suspected to be the key toxicant in the samples.
Biomarkers for Mercury Exposure in Tropical Estuarine Fish
Authors: Rodrigues A. P. C. , Maciel P. O. , Pereira da Silva L. C. C. , Albuquerque C. , Inácio A. F. , Freire M. , Linde A. R. , Almosny N. R. P. , Andreata J. V. , Bidone E. D. , Castilhos Z. C.
Published: September 2010

Several studies have evaluated human risks due mercury (Hg) exposure through fish consumption. However, relatively few studies have explored effects of environmental Hg concentrations in biota, especially tropical fish species. The aim of this work was to assess in situ hematological, biochemical and genotoxic effects in tropical fish due to environmental exposure to mercury in estuarine ecosystems. A total of 282 fishes were collected from September 2003 to October 2005 in two estuarine areas: Ribeira Bay (reference area - 22° 55’ to 23° 02’ S and 44° 18’ to 44° 26’ W) and Guanabara Bay (highly impacted area by human activities - 22° 40’ to 23° 00’ S and 43° 00’ to 43° 20’ E). Total mercury levels in fish from Guanabara were twice higher than in Ribeira bay for the catfish species Genidens genidens (Ariidae), with significant differences among areas after standardization using length intervals (exposure time indicator). The species Haemulon steindachneri (Haemulidae) showed the highest mercury concentration, reflecting its position in trophic chain. Among effect biomarkers, only haematocrit, global leucometry and micronucleus assays seemed to reflect the differences on mercury exposure among areas, what may support their use for evaluations of fish exposure to mercury compounds. However, it’s necessary both laboratory experiments to establish cause-effect relationship and a continuous in situ study to obtain more information, involving more trophic levels, searching for sensible species to mercury exposure.
Appraisal of Copepod Acartia tonsa (Dana, 1849) as a Chronic Toxicity Test Organism
Authors: Ihara P. M. , Pinho G. L. L. , Fillmann G.
Published: September 2010

Ecotoxicological tests have been used as an important tool in assessing the environmental quality. In order to improve the use of marine and estuarine native organisms in chronic toxicity tests, this study evaluated the potential of the copepod Acartia tonsa in reproduction test. The sensitivity of A. tonsa was determined by exposing adults to 0.5, 0.75, 1.0, 1.5, 2.0 and 2.5 mg.L-1 of zinc sulphate (ZnSO4.7H2O). The production of eggs per female was measured after 48 hours of exposure, resulting in the EC50 of 2.05 mg.L-1 of zinc sulphate (CI 95% = 1.77 - 2.20 mg.L-1). Acute toxicity test was also performed, exposing adults to 2.5, 5.0, 7.5, 10, 12.5 and 15 mg.L-1 ZnSO4.7H2O. Compared to acute effects, the chronic test was 1.9 lower than the lethal concentration (LC50 of 3.80 mg.L-1). The sensitivity response of A. tonsa exposed to zinc presented an EC50 3 to 4 times higher than the others test organism described in the literature, so further studies are needed to improve sensitivity by developing and applying other sublethal endpoints.
The potential influence of Asian and African mineral dust on ice, mixed-phase and liquid water clouds
Authors: Wiacek A. , Peter T. , Lohmann U.
Published: September 2010

Abstract. This modelling study explores the availability of mineral dust particles as ice nuclei for interactions with ice, mixed-phase and liquid water clouds, also tracking the particles' history of cloud-processing. We performed 61 320 one-week forward trajectory calculations originating near the surface of major dust emitting regions in Africa and Asia using high-resolution meteorological analysis fields for the year 2007. Dust-bearing trajectories were assumed to be those coinciding with known dust emission seasons, without explicitly modelling dust emission and deposition processes. We found that dust emissions from Asian deserts lead to a higher potential for interactions with high ice clouds, despite being the climatologically much smaller dust emission source. This is due to Asian regions experiencing significantly more ascent than African regions, with strongest ascent in the Asian Taklimakan desert at ~25%, ~40% and 10% of trajectories ascending to 300 hPa in spring, summer and fall, respectively. The specific humidity at each trajectory's starting point was transported in a Lagrangian manner and relative humidities with respect to water and ice were calculated in 6-h steps downstream, allowing us to estimate the formation of liquid, mixed-phase and ice clouds. Downstream of the investigated dust sources, practically none of the simulated air parcels reached conditions of homogeneous ice nucleation (T≲−40 °C) along trajectories that have not experienced water saturation first. By far the largest fraction of cloud forming trajectories entered conditions of mixed-phase clouds, where mineral dust will potentially exert the biggest influence. The majority of trajectories also passed through atmospheric regions supersaturated with respect to ice but subsaturated with respect to water, where so-called "warm ice clouds" (T≳−40 °C) theoretically may form prior to supercooled water or mixed-phase clouds. The importance of "warm ice clouds" and the general influence of dust in the mixed-phase cloud region are highly uncertain due to both a considerable scatter in recent laboratory data from ice nucleation experiments, which we briefly review in this work, and due to uncertainties in sub-grid scale vertical transport processes unresolved by the present trajectory analysis. For "classical" cirrus-forming temperatures (T≲−40 °C), our results show that only mineral dust ice nuclei that underwent mixed-phase cloud-processing, most likely acquiring coatings of organic or inorganic material, are likely to be relevant. While the potential paucity of deposition ice nuclei shown in this work dimishes the possibility of deposition nucleation, the absence of liquid water droplets at T≲−40 °C makes the less explored contact freezing mechanism (involving droplet collisions with bare ice nuclei) highly inefficient. These factors together indicate the necessity of further systematic studies of immersion mode ice nucleation on mineral dust suspended in atmospherically relevant coatings.
Comparison of TOMS retrievals and UVMRP measurements of surface spectral UV radiation in the United States
Authors: Xu M. , Liang X.-Z. , Gao W. , Krotkov N.
Published: September 2010

Abstract. Surface noontime spectral ultraviolet (UV) irradiances during May-September of 2000–2004 from the total ozone mapping spectrometer (TOMS) satellite retrievals are systematically compared with the ground measurements at 27 climatological sites maintained by the USDA UV-B Monitoring and Research Program. The TOMS retrievals are evaluated by two cloud screening methods and local air quality conditions to determine their bias dependencies on spectral bands, cloudiness, aerosol loadings, and air pollution. Under clear-sky conditions, TOMS retrieval biases vary from −3.4% (underestimation) to 23.6% (overestimation). Averaged over all sites, the relative mean biases for 305, 311, 325, and 368 nm are respectively 15.4, 7.9, 7.6, and 7.0% (overestimation). The bias enhancement for 305 nm by approximately twice that of other bands likely results from absorption by gaseous pollutants (SO2, O3), and aerosols that are not included in the TOMS algorithm. For all bands, strong positive correlations of the TOMS biases are identified with aerosol optical depth, which explains nearly 50% of the variances of TOMS biases. The more restrictive in-situ cloud screening method reduces the biases by 3.4–3.9% averaged over all sites. This suggests that the TOMS biases from the in-situ cloud contamination may account for approximately 25% for 305 nm and 50% for other bands of the total bias. The correlation coefficients between total-sky and clear-sky biases across 27 sites are 0.92, 0.89, 0.83, and 0.78 for 305, 311, 325, and 368 nm, respectively. The results show that the spatial characteristics of the TOMS retrieval biases are systematic, representative of both clear and total-sky conditions.
Validating the MYSTIC three-dimensional radiative transfer model with observations from the complex topography of Arizona's Meteor Crater
Authors: Mayer B. , Hoch S. W. , Whiteman C. D.
Published: September 2010

Abstract. The MYSTIC three-dimensional Monte-Carlo radiative transfer model has been extended to simulate solar and thermal irradiances with a rigorous consideration of topography. Forward as well as backward Monte Carlo simulations are possible for arbitrarily oriented surfaces and we demonstrate that the backward Monte Carlo technique is superior to the forward method for applications involving topography, by greatly reducing the computational demands. MYSTIC is used to simulate the short- and longwave radiation fields during a clear day and night in and around Arizona's Meteor Crater, a bowl-shaped, 165-m-deep basin with a diameter of 1200 m. The simulations are made over a 4 by 4 km2 domain using a 10-m horizontal resolution digital elevation model and meteorological input data collected during the METCRAX (Meteor Crater Experiment) field experiment in 2006. Irradiance (or radiative flux) measurements at multiple locations inside the crater are then used to evaluate the simulations. MYSTIC is shown to realistically model the complex interactions between topography and the radiative field, resolving the effects of terrain shading, terrain exposure, and longwave surface emissions. The effects of surface temperature variations and of temperature stratification within the crater atmosphere on the near-surface longwave irradiance are then evaluated with additional simulations.