target zones and interest rate variability abstract for narrow exchange rate bands and for reasonable parameter values the interest rate differential s asymptotic unconditional variability is increasing in the width of the exchange rate band whereas for wide exchange rate bands it is slowly decreasing in the exchange rate band the interest rate differential s instantaneous conditional variability is decreasing in the width of the exchange rate band a narrow target zone differs from a completely fixed exchange rate regime in that the interest rate differential s instantaneous standard deviation is high and even increases when the zone narrows

witchcraft weather and economic growth in renaissance europe between the thirteenth and nineteenth centuries as many as one million individuals in europe were executed for the crime of witchcraft the majority of the trials and executions took place during the sixteenth and seventeenth centuries during this period the speed and volume of executions were astonishing in one german town as many as 400 people were killed in a single day midelfort 1972 the trials were ubiquitous conducted by both ecclesiastical and secular courts by both catholics and protestants the victims were primarily women primarily poor and disproportionately widows the persecutions took place throughout europe starting and ending earlier in southwest europe than in the northern and eastern areas and spread even across the atlantic ocean to salem massachusetts although witchcraft trials in europe and america largely ended by the late eighteenth century witchcraft accusations and killings still take place in many countries today particularly in the developing world for example witchcraft is often blamed for aids deaths in sub saharan africa ashforth 2001 and miguel 2003 shows that negative economic shocks are associated with increases in witch killing in modern tanzania belief in the witch and fear of her is enduring while much work has been done on the motivations behind the european trials the large scale causes remain unknown the existing work has primarily been concerned with the factors that played into trials on a small scale why a certain individual was targeted or why a certain type of individual was targeted in a given area this work has indicated that there was a diverse set of issues that played into trials on an individual level more broadly however there are few causal explanations for why witchcraft trials happened at all and on such a large scale in so many

witchcraft beliefs as a cultural legacy of the atlantic slave trade evidence from two continents abstract this paper argues that the historical slave trade contributed to the propagation of persistent witchcraft beliefs on both sides of the atlantic ocean and establishes two key empirical patterns first it shows that in sub saharan africa representatives of ethnic groups which were more heavily exposed to the atlantic slave trade in the past are more likely to believe in witchcraft today thus establishing a link between historical trauma and contemporary culture second exploring the role of the slave trade in cultural transmission across continents this paper finds that afro descendants in modern latin america are substantially more likely to believe in witchcraft relative to other ancestral groups moreover accounting for ancestry and other relevant factors people residing in regions historically more reliant on african slave labor are also more likely to be witchcraft believers these findings support ethnographic narratives on the connection between slave trade slavery and the entrenchment of witchcraft beliefs and shed light on the nature of these beliefs and related practices as a cultural framework for interpreting misfortune and a mechanism of enslavement in local communities

the implications of industrial development for diversification of fuels abstract the central role of energy in economic growth and development is substantiated by both theory and data much of the analysis of energy in economics has focused on the study of the aggregate output here we deviate from this approach and study the role of fuel diversification in industrial development we build the energy space describing the space of energy technologies which a country can use in the production of manufacturing goods as countries grow they diversify their industries producing more diverse products over time we show that the process is accompanied by diversification of fuels which countries use in the manufacturing sector in particular countries move in the energy space by adopting novel fuels while their movements can be linked to structural changes in the industry over time countries build unique production capabilities which drives divergence in fuel diversity between countries our results provide insight into the limits of fuel substitution in the manufacturing sector as well as they carry important implications for the assessment of potential reductions in co 2 emissions in the future

target zones and exchange rate dynamics this paper develops a simple model of exchange rate behavior under a target zone regime it shows that the expectation that monetary policy will be adjusted to limit exchange rate variation affects exchange rate behavior even when the exchange rate lies inside the zone and is thus not being defended actively somewhat surprisingly the analysis of target zones turns out to have a strong formal similarity to problems in option pricing and investment under uncertainty

diversification criteria for power systems abstract growing power demand fuel availability and prices technology changes the environmental impacts of energy consumption the changing regulatory environments and the uncertainties around such elements make the planning for optimal power mix a challenging task the diversity approach is advocated as a most appropriate planning methodology for the optimal energy mix hickey et al 2010 shannon wiener index swi which is the most cited diversity metric has been used to assess power systems diversity mainly from an energy perspective to our best knowledge there is no rigorous justification why energy has been the main variable used in diversification exercises rather than other variables such as capacity we use a stylized power generation framework to show that diversity based on energy or capacity could lead to different outcomes in terms of vulnerability to fuel exposure among others we also introduce a shannon wiener index ratio swir that we believe captures better the diversity of a power system compared to the standard swi

the long term effect of demographic shocks on the evolution of gender roles evidence from the transatlantic slave trade can demographic shocks affect the long run evolution of female labor force participation and gender norms this paper traces current variation in women s participation in the labor force within sub saharan africa to the emergence of a female biased sex ratio during the centuries of the transatlantic slave trade this historical shock affected the division of labor along gender lines in the remaining african population as women substituted for the missing men by taking up areas of work that were traditionally male tasks by exploiting variation in the degree to which different ethnic groups were affected by the transatlantic slave trade i show that women whose ancestors were more exposed to this shock are today more likely to be in the labor force have lower levels of fertility and are more likely to participate in household decisions the marriage market and the cultural transmission of internal norms across generations represent important mechanisms explaining this long run persistence

quantifying the supplier portfolio diversity of embodied energy strategic implications for strengthening energy resilience this paper investigates energy resilience of countries by quantifying the supplier diversification of both direct and embodied energy import in particular we quantify two approaches to diversify a country s supplier portfolio by lowering the dependency on each supplier portfolio diversification and by having embodied energy suppliers that are different from its direct energy suppliers portfolio differentiation we examine possibilities for strategic utilization of embodied energy trade to compensate for low diversity of direct energy trade for three types of fossil resources coal oil and gas we find that the diversity of embodied energy import is much greater than that of direct energy import of the three energy resources coal enables countries to adopt portfolio diversification and portfolio differentiation more than gas and oil our results suggest embodied energy can be considered as a transfer of energy resources across national borders that can directly benefit from the diversity of the world energy production by skipping the limited diversity of the world energy export

regulation in the european community all governments regulate economic activity in their own countries the single european market will involve a significant transfer of regulatory activity from member states to the european community as well as the initiation of regulatory activity in certain areas that have not previously been subject to regulation at all including the activities of member states themselves as in taxation or the provision of subsidies to industry why should governments wish to make such a transfer of powers what do they have to gain

the slave trade and the origins of mistrust in africa in a recent study nunn 2008 examines the long term impacts of africa s slave trade he finds that the slave trade which occurred over a period of more than 400 years had a significant negative effect on long term economic development although the article arguably identifies a negative causal relationship between the slave trade and income today the analysis is unable to establish the exact causal mechanisms underlying this reduced form relationship in this article we examine one of the channels through which the slave trade may affect economic development today combining contemporary individual level survey data with historical data on slave shipments by ethnic group we ask whether the slave trade caused a culture of mistrust to develop within africa initially slaves were captured primarily through state organized raids and warfare but as the trade progressed the environment of ubiquitous insecurity caused individuals to turn on others including friends and family members and to kidnap trick and sell each other into slavery sigismund wilhelm koelle 1854 p e h hair 1965 charles piot 1996 we hypothesize that in this environment a culture of mistrust may have evolved which may persist to this day we show that current differences in trust levels within africa can be traced back to the transatlantic and indian ocean slave trades combining contemporary individual level survey data with historical data on slave shipments by ethnic group we find that individuals whose ancestors were heavily raided during the slave trade are less trusting today evidence from a variety of identification strategies suggests that the relationship is causal examining causal mechanisms we show that most of the impact of the slave trade is through factors that are internal to the individual such as cultural norms beliefs and values jel j15 n57 z13

diversity and security in uk electricity generation the influence of low carbon objectives abstract we explore the relationship between low carbon objectives and the strategic security of electricity in the context of the uk electricity system we consider diversity of fuel source mix to represent one dimension of security robustness against interruptions of any one source and apply two different diversity indices to the range of electricity system scenarios produced by the uk government and independent researchers our results show that low carbon objectives are uniformly associated with greater long term diversity in uk electricity generation with reference to data on wind generation we also consider the impact of source variability on a second dimension of security the reliability of generation availability we conclude that this does not undermine our fundamental conclusion that low carbon scenarios are associated with greater strategic security of supply in uk electricity we discuss reasons for this result explore sensitivities and briefly discuss possible policy instruments associated with diversity and their limitations

the economic origins of the evil eye belief the evil eye belief is a widespread superstition according to which people can cause harm by a mere envious glance at coveted objects or their owners this paper argues that such belief originated and persisted as a useful heuristic under conditions in which envy was likely to trigger destructive behavior and the avoidance of other people s envy effectively prescribed by the evil eye belief was a proper response to that threat we hypothesize that in weakly institutionalized societies wealth differentiation and vulnerability of productive assets were the key factors enabling envy induced destructive behavior and contributing to the emergence and spread of the evil eye belief as a cultural defense mechanism evidence from small scale preindustrial societies shows that there is indeed a robust positive association between the incidence of the belief and measures of wealth inequality controlling for potential confounding factors such as patterns of spatial and cross cultural diffusion and various dimensions of early economic development furthermore the evil eye belief is more prevalent in agro pastoral societies that tend to sustain higher levels of inequality and where vulnerable material wealth plays a dominant role in the subsistence economy

equilibrium models displaying endogenous fluctuations and chaos abstract this paper surveys current developments in dynamic general equilibrium theory concerned with conditions under which endogenous fluctuations are possible existing contributions are divided into two classes the larger one consists of models with a unique perfect foresight equilibrium while the second includes models where equilibrium is indeterminate and the set of equilibria involving endogenous fluctuations includes sunspots equilibria while the two classes of models involve oscillations of different natures and with different policy implications we show that both are consistent with optimizing behavior and competitive equilibrium

slavery education and inequality abstract we investigate the effect of slavery on the current level of income inequality across us counties we find that a larger proportion of slaves over population in 1860 persistently increases inequality and in particular inequality across races we also show that a crucial channel of transmission from slavery to racial inequality is human capital accumulation i e current inequality is primarily influenced by slavery through the unequal educational attainment of blacks and whites finally we provide suggestive evidence that the underlying links run through the political exclusion of former slaves and the resulting negative influence on the local provision of education

resilience and electricity systems a comparative analysis electricity systems have generally evolved based on the natural resources available locally few metrics exist to compare the security of electricity supply of different countries despite the increasing likelihood of potential shocks to the power system like energy price increases and carbon price regulation this paper seeks to calculate a robust measure of national power system resilience by analysing each step in the process of transformation from raw energy to consumed electricity countries with sizeable deposits of mineral resources are used for comparison because of the need for electricity intensive metals processing we find that shifts in electricity intensive industry can be predicted based on countries power system resilience

the historical slave trade and firm access to finance in africa access to finance helps explain the link between the historical african slave trade and current gross domestic product we first present mistrust weakened institutions and ethnic fractionalization as plausible historical channels linking the slave trade to modern finance and development we then show i the slave trade is consistently linked to reduced access to the formal and trade credit needed by modern firms ii this shortage particularly reduces capital investment in smaller firms not in business groups and iii the slave trade cannot explain most other business obstacles suggesting that long term societal shocks are exceptionally important for finance received december 16 2014 editorial decision june 29 2017 by editor philip strahan

limits to the value of external costs based on recent insights from the field of risk analysis this paper examines some of the difficulties encountered in attempts to characterise the environmental effects of energy options as monetary externalities more than 20 different dimensions of environmental appraisal are identified and discussed in relation to the historic literature on risk assessment and a number of recent influential environmental valuation studies a survey is conducted of the results obtained over more than a decade for the external environmental costs of electricity supply options theoretical and methodological criticisms are lent support by the finding that environmental valuation results vary over a very wide range of values yielding a variety of rank orderings for the different generating options in addition the values derived for energy externalities are found to be vulnerable to the possible influence of a price imperative the paper concludes by pointing to approaches to the social appraisal of generating technologies which offer greater transparency rigour and accessibility in addressing plural and intrinsically subjective value judgements concerning the different forms and dimensions of environmental effects

capital budgeting under uncertainty an extended goal programming approach mathematical programming techniques have long been recognized as the most suitable approach to the complex problem of capital budgeting in corporations this is because contrary to conventional single project appraisal techniques such as the net present value method financial planners do not normally engage in project by project analysis to determine the projects that would be included in capital budgets in addition the existing chance constrained both single and multiple objectives models developed to deal with the problem of uncertainty in capital budgeting are grossly defective since they indeed address the problem of risk rather than uncertainty this paper presents an extended goal programming methodology to address the problem of capital budgeting under uncertainty to overcome the defects of chance constrained capital budgeting models in particular since financial planners frequently deal with the complex problem of capital budgeting by aggregating large numbers of small investment proposals into families of large projects the paper presents necessary and sufficient conditions for the acceptance of a set of investment projects by a business enterprise the results indicate that under uncertainty firms faced with capital rationing are less economically efficient than others that are not so faced also the results show that optimal allocation policy under uncertainty requires the actual discount rate to be greater than the market cost of capital a finding which is consistent with corporate finance practice

energy security and improvements in the function of diversity indices taiwan energy supply structure case study abstract facing the risk and uncertainty inherent in social and economic development many countries have adopted an energy supply diversification strategy in their energy security policy to control the energy import risk and cost to ensure that sufficient energy can be obtained at an affordable price level diversification helps the energy system respond to external changes and shocks diversification can also lessen the vulnerability of a single energy source to supply shocks and the market power of various energy supply sources this study develops the diversity reliability index and co vary diversity reliability index based on the hirschman herfindahl and shannon wiener indices investigates the contribution of different energy sources to the energy system and analyzes the covariance between various energies and their impacts on energy security to determine the impact of energy diversity in reducing the risk of energy supply shortages and cost fluctuations

the long term effects of africa s slave trades can part of africa s current underdevelopment be explained by its slave trades to explore this question i use data from shipping records and historical documents reporting slave ethnicities to construct estimates of the number of slaves exported from each country during africa s slave trades i find a robust negative relationship between the number of slaves exported from a country and current economic performance to better understand if the relationship is causal i examine the historical evidence on selection into the slave trades and use instrumental variables together the evidence suggests that the slave trades have had an adverse effect on economic development

a retrospective analysis of benefits and impacts of u s renewable portfolio standards abstract as states consider revising or developing renewable portfolio standards rps they are evaluating policy costs benefits and other impacts we present the first u s national level assessment of state rps program benefits and impacts focusing on new renewable electricity resources used to meet rps compliance obligations in 2013 in our central case scenario reductions in life cycle greenhouse gas emissions from displaced fossil fuel generated electricity resulted in 2 2 billion of global benefits health and environmental benefits from reductions in criteria air pollutants sulfur dioxide nitrogen oxides and particulate matter 2 5 were even greater estimated at 5 2 billion in the central case further benefits accrued in the form of reductions in water withdrawals and consumption for power generation finally although best considered resource transfers rather than net societal benefits new renewable electricity generation used for rps compliance in 2013 also supported nearly 200 000 u s based gross jobs and reduced wholesale electricity prices and natural gas prices saving consumers a combined 1 3 4 9 billion in total the estimated benefits and impacts well exceed previous estimates of rps compliance costs

the empire is dead long live the empire long run persistence of trust and corruption in the bureaucracy we hypothesise that the habsburg empire with its well respected administration increased citizens trust in local public services in several eastern european countries communities on both sides of the long gone habsburg border have shared common formal institutions for a century now we use a border specification and a two dimensional geographic regression discontinuity design to identify from individuals living within a restricted band around the former border we find that historical habsburg affiliation increases current trust and reduces corruption in courts and police falsification tests of spuriously moved borders geographic and pre existing differences and interpersonal trust corroborate a genuine habsburg effect

are economic time series asymmetric over the business cycle it has long been argued that major cyclical variables such as the unemployment rate display an asymmetric behavior over various phases of the business cycle the paper provides a statistical test for this hypothesis using the framework of finite state markov processes i implement a test to see if the behavior of the unemployment rate is characterized by sudden jumps and slower drops it is argued that the framework provided in the paper can also be used to test other sample path properties of economic time series

the evolution of culture and institutions evidence from the kuba kingdom we use variation in historical state centralization to examine the long term impact of institutions on cultural norms the kuba kingdom established in central africa in the early 17th century by king shyaam had more developed state institutions than the other independent villages and chieftaincies in the region it had an unwritten constitution separation of political powers a judicial system with courts and juries a police force a military taxation and significant public goods provision comparing individuals from the kuba kingdom to those from just outside the kingdom we find that centralized formal institutions are associated with weaker norms of rule following and a greater propensity to cheat for material gain this finding is consistent with recent models where endogenous investments to inculcate values in children decline when there is an increase in the effectiveness of formal institutions that enforce socially desirable behavior consistent with such a mechanism we find that kuba parents believe it is less important to teach children values related to rule following behaviors

dynamic s s economies in this paper the authors provide a framework to study the aggregate dynamic behavior of an economy where individual units follow s s policies and are subject to aggregate and idiosyncratic shocks they characterize structural and stochastic heterogeneities that ensure convergence of the economy s aggregate to that of its stochastic frictionless counterpart determine the speed at which convergence takes place and describe the transitional dynamics of this economy they study the evolution of the economy s aggregate and the evolution of the difference between this aggregate and that of the difference between this aggregate and that of an economy without microeconomic friction where the latter pertains to a situation where individual units adjust with no delay to all shocks copyright 1991 by the econometric society

poverty and witch killing many observers have noted that poverty and violence go hand in hand there is a strong negative relationship between economic growth and crime across countries as well as across districts in india and a link between low income and the occurrence of civil war 1 yet existing studies are typically unable to resolve the key econometric identification issues of omitted variable bias and endogeneity to illustrate the unobserved quality of local government institutions may affect both income growth and crime rates and poverty could lead to violence if desperate people with nothing to lose commit more crimes but violence itself may in turn affect economic productivity this paper uses local rainfall variation to identify the impact of income shocks on murder in a rural tanzanian district 2 extreme rainfall resulting in drought or floods is exogenous and is associated with poor harvests and near famine conditions in the region and a large increase in the murder of witches there are twice as many witch murders in years of extreme rainfall as in other years the victims are nearly all elderly women typically killed by relatives these econometric results across 11 years in 67 villages provide novel evidence on the role of income shocks in causing violent crime and religious violence in particular and also provide insights into witchcraft an important social phenomenon in africa rarely studied by economists the view that economic conditions are a driving force behind witch murders is bolstered by the fact that most witch killing in tanzania takes place in poor rural areas largely dependent on rain fed agriculture and that most victims in our sample are from poor households however it is difficult to definitively disentangle this income shock theory from alternative socio cultural explanations the concentration of tanzanian witch murders in a region dominated by one particular ethnic group the sukuma and the especially high number of witch murders in villages where indigenous religious beliefs are strong both point to the important role of non economic factors economic theories and cultural theories are perhaps best viewed as complements the empirical findings demonstrate the power of economics to rationalize a phenomenon that has previously been understood almost solely through a socio cultural lens 3

fuel mix diversification incentives in liberalized electricity markets a mean variance portfolio theory approach monte carlo simulations of gas coal and nuclear plant investment returns are used as inputs of a mean variance portfolio optimization to identify optimal base load generation portfolios for large electricity generators in liberalized electricity markets we study the impact of fuel electricity and co2 price risks and their degree of correlation on optimal plant portfolios high degrees of correlation between gas and electricity prices as observed in most european markets reduce gas plant risks and make portfolios dominated by gas plant more attractive long term power purchase contracts and or a lower cost of capital can rebalance optimal portfolios towards more diversified portfolios with larger shares of nuclear and coal plants

diversity and ignorance in electricity supply investment addressing the solution rather than the problem the need for diversity has been cited as a rationale for important recent investment decisions in the uk electricity supply sector it is invoked as the principal argument for continuing major government intervention yet there exists no formal analytical basis for the concept why is diversity good what is meant by diversification what is it that must be diversified what trade off should be struck between diversity and other measures of performance the resulting ambiguity causes confusion and is vulnerable to special pleading despite this this paper argues that diversification offers a superior alternative to probabilistic approaches towards uncertainty and ignorance in electricity supply investments and proposes a formal analytical approach a quantitative index of diversity is borrowed from information theory and used to derive a value for the government s implicit willingness to pay for diversity in the uk electricity supply mix this is then applied in a pilot exercise to the problem of optimizing the diversity and financial performance of the supply portfolio although provisional the results are relevant to the government s forthcoming nuclear review particularly in assessing the relative levels of support for nuclear power and renewable energy

fossil fuel dependence and vulnerability of electricity generation case of selected european countries abstract this paper analyses the diversity of fuel mix for electricity generation in selected european countries and investigates how the fuel bill has changed as a share of gdp between 1995 and 2005 the drivers of fuel dependence related vulnerability are determined using laspeyres index decomposition a what if analysis is carried out to analyse the changes in the vulnerability index due to changes in the drivers and a scenario analysis is finally used to investigate the future vulnerability in the medium term the paper finds that the british and the dutch electricity systems are less diversified compared to three other countries analysed the gas dependence of the dutch and italian systems made them vulnerable but the vulnerability increased in all countries in recent years gas price and the level of dependence on gas for power generation mainly influenced the gas vulnerability the united kingdom saw a substantial decline in its coal vulnerability due to a fall in coal price and coal dependence in electricity generation the scenario analysis indicates that uk is likely to face greater gas vulnerability in the future due to increased gas dependence in electricity generation and higher import dependence

long term energy services security what is it and how can it be measured and valued abstract the paper reviews some recent approaches towards measuring the extent of long term energy security and security externality valuation it starts out to discuss the contextual connotations of notions of energy security in medium to long term time frames and reviews some indicators that have been proposed to quantify it special attention is paid to two of these approaches which the authors helped to develop i e diversity based indices and the supply demand index the paper takes issue with conventional welfare economic approaches that neglect i the scope on the demand side for raising security and ii negative feedback mechanisms of socio political impacts of international rent transfers in fossil fuels exporting countries the concept of energy services security is proposed with a demand side focus this enables application of an integrated approach to gauge the resilience of a society to meet the needs of its population for energy services over longer timescales ahead from various interrelated perspectives propositions are made on the attribution of security externalities to the use of fossil fuels policies and suggestions for further improvements of measures for energy services security

climate and the slave trade african societies exported more slaves in colder years lower temperatures reduced mortality and raised agricultural yields lowering slave supply costs our results help explain african participation in the slave trade which predicts adverse outcomes today we use an annual panel of african temperatures and port level slave exports to show that exports declined when local temperatures were warmer than normal this result is strongest where african ecosystems are least resilient to climate change cold weather shocks at the peak of the slave trade predict lower economic activity today we support our interpretation using the histories of whydah benguela and mozambique

good bad and ugly colonial activities do they matter for economic development levels of development vary widely within countries in the americas we argue that part of this variation has its roots in the colonial era when colonizers engaged in different economic activities in different regions of a country we present evidence consistent with the view that bad activities those that depended heavily on labor exploitation led to lower economic development today than good activities those that did not rely on labor exploitation our results also suggest that differences in political representation but not in income inequality or human capital could be the intermediating factor between colonial activities and current development

nonlinear dynamics and econometrics an introduction the empirical modelling of economic time series is dominated by methods that assume linearity of the underlying dynamic economic system the so called frisch slutsky paradigm the main a priori argument in favour of linearity and the reason for its original adoption is its simplicity autoregressive models can be estimated using standard regression packages and there is now a wide range of computer software packages available to estimate models with linear moving average components the dynamics contained in estimated models can be completely characterized by their impulse response functions and directly related to linear models of the macroeconomy the dominance of the frisch slutsky paradigm is not based on any strong a priori belief that the economic system is linear indeed once curvature is introduced into utility functions and or production functions nonlinearity is pervasive in theoretical dynamic models hence the shortage of closed form solutions nor is it based on any convincing empirical evidence that actual economic time series are best described as linear stochastic processes the lq optimization approach namely linear constraints and quadratic objective functions which underlies most econometric applications either implicitly or explicitly is undoubtedly attractive on analytical and computational grounds but can be highly deficient in areas where economic behaviour is dominated by asymmetric costs of adjustments irreversibilities transaction costs or institutional and physical rigidities the challenge facing applied econometrics in dealing with these issues is truly immense reliable statistical techniques are required for detecting dynamic nonlinearities stochastic optimization models that are capable of capturing the primary sources of dynamic nonlinearities and are suitable for empirical analysis need to be developed the possible effects of temporal aggregation and aggregation across commodities and agents need to be worked out in the context of nonlinear dynamic models these are complicated issues solutions to some of which have eluded us even in the case of linear models and promise to be far more complicated when we enter the realm of nonlinear dynamic models it is therefore natural to expect that real progress in the area of nonlinear dynamic econometric models will be slow and hard to come by nevertheless the past two decades have witnessed important advances in the mathematical and statistical analysis of dynamic systems particularly in physics epidemiology and meteorology many of these developments have already found their way into economics and

vulnerability of the economy to the potential disturbances of energy supply a logic based model with application to the case of china the disturbances of energy supply that may result from both external and domestic events create a significant threat for national economy due to potential impacts on the productivity employment and overall economic growth building scenarios of the economy s vulnerability to these disturbances is delicate because of the significant number of interrelated factors that should be taken into consideration in this paper a logic based model lbm is developed which allows for defining exploring and assessing the determinants and the indicators of the economy s vulnerability related to the energy supply disturbances within a coherent scenarios assessment framework the proposed model is illustrated with the case of china after developing the general framework three particular scenarios are investigated based on the case study the performance and limitations of the model are analyzed and its ability to evaluate national energy policies is discussed finally some recommendations for further improvements are made

why being wrong can be right magical warfare technologies and the persistence of false beliefs across human societies one sees many examples of deeply rooted and widely held beliefs that are almost certainly untrue examples include beliefs about witchcraft magic ordeals and superstitions why are such incorrect beliefs so prevalent and how do they persist we consider this question through an examination of superstitions and magic associated with conflict in the eastern democratic republic of the congo focusing on superstitions related to bulletproofing we provide theory and case study evidence showing how these incorrect beliefs persist although harmful at the individual level we show that they generate pareto efficient outcomes that have group level benefits

resilience weather and dynamic adjustments in agroecosystems the case of wheat yield in england the paper presents an investigation of agroecosystem dynamics with an application to wheat yield data in england over the period 1885 2012 the analysis relies on a threshold quantile autoregressive model the model allows for lag effects to vary across quantiles of the distribution as well as with the values taken by the lagged variables the analysis documents the dynamics and persistence of yield adjustments to shocks the estimates indicate the presence of dynamic instability in the lower quantile of the distribution the analysis shows that after controlling for the role of technological trend wheat yield exhibits resilience to adverse weather shocks

valuing diversity in energy supply abstract there is renewed interest in the role of supply diversity in promoting energy security this paper explores ways of valuing diversity a possible incentive mechanism for promoting diversity which takes account of underlying disparities between different technology options is developed the mechanism provides a way of trading off cost and diversity and results in an efficient cost diversity frontier by analogy with financial portfolio theory if all technologies are believed to be equally disparate the appropriate mechanism is a levy imposed on market share if the technologies are not equally disparate the levy needs to be adjusted by technology specific multipliers that take account of levels of disparity and patterns of market share the analysis is applied to two stylised situations in the long run equilibrium case the implications of both different patterns of disparity and different values attached to diversity are investigated the paper also explores the implications of applying such a mechanism to the current great britain electricity system the implications in terms of financial flows for both the market as a whole and for individual operators are investigated finally the appropriateness of such a mechanism in the light of other policy goals and possible future research directions is discussed

ownership unbundling in electricity distribution the case of the netherlands this paper addresses the merits of ownership unbundling of distribution networks as exemplified in the case of the netherlands in essence this problem concerns the question of whether the operation and management of electricity distribution networks in this country will evolve into a market driven commodity business or remain a genuine public utility task in order to deal with this problem a framework is developed that enables the classification of different institutional regimes depending on the nature of the institutional regime this case of the netherlands illustrates how certain aspects of the liberalisation of the electricity sector can become vitally important to the continuing process of restructuring

energy planning and modern portfolio theory a review abstract modern portfolio theory mpt stands as a widely accepted methodology to meet the challenges associated with the definition of energy planning for a particular territory or region energy planning is thus framed as an investment selection problem mpt is characterized by having a wider capacity and conceptual richness than the other previously used methodologies such as the individual least cost alternative the portfolio approach is based on solving for an objective function that seeks to minimize either the cost or the risk of the portfolio subject to different constraints considering that real electricity generation assets can be defined in terms of cost or return and economic risk for each alternative technology the relevant portfolios are the result of solving the optimization model to determine the efficient cost risk frontier the work presented here consists of an exhaustive review of the literature in relation to the application of mpt methodology to the field of energy planning and electricity production a new classification is proposed from a financial perspective of the selection of investments from the preceding studies it delves deeper into the explanation of the limits to the methodology and into the concept of risk which is key from both a financial and an energy perspective the main methodological contributions found in the literature are examined that are aimed at improving the capacity of the model and adjusting it to the reality of the electricity market finally conclusions are provided from the works analyzed in terms of renewable technologies and the policy implications derived from them in most studies a preference has been shown for the inclusion of renewable technologies in the efficient portfolios however in order to implement the decision to increase the share of renewable technologies greater flexibility in the interconnection capacity between states and in storage capacity is needed

the impact of the transatlantic slave trade on ethnic stratification in africa in the last 15 years economists and economic historians have argued that africa has undergone a reversal of fortune and that ethnic fragmentation is a significant cause of africa s underdevelopment in this article we join these narratives by arguing that the transatlantic slave trade increased the degree of ethnic heterogeneity in africa today using both correlational and causal instrumental variables analysis we find an economically and statistically significant positive relationship between slave exports and ethnic heterogeneity this relationship is robust to changes in the scheme for drawing ethnic boundaries and the choice of observational unit

distributed generation and distribution market diversity in europe the unbundling of the electricity power system will play a key role on the deployment of distributed generation dg in european distribution systems evolving towards smart grids the present paper firstly reviews the relevant european union eu regulatory framework specific attention is paid to the concept of unbundling of power distribution sector in europe afterwards the focus is on the current state of penetration of dg technologies in the eu member states and the corresponding interrelations with distribution features a comparison between the unbundling of the distribution and supply markets using econometric indicators such as the herfindahl hirschmann ihh and the shannon wiener isw indices is then presented finally a comparative analysis between these indices and the current level of penetration of distributed generation in most eu is shown policy recommendations conclude the paper