fixed costs efficient resource management and conservation this article develops a framework to analyze the impacts on resource development of efficient management practices that account for possible resource conserving technological changes compared with the traditional management practice ignoring these changes efficient management may not delay or reduce resource development depending on the level of the changes under efficient management a higher probability of resource conserving technologies may not delay or reduce resource development these ambiguities are due to the existence of fixed and increasing marginal costs in resource development

international cooperation behind the veil of uncertainty the case of transboundary acidification the complexities of international environmental problems are only poorly understood hence decision makers have to negotiate about abatement measures even though they do not know the true model of the ecological system and have only a rough idea about the costs and benefits of their action it will be analysed to what extent this kind of model uncertainty where players do not only have incomplete information about the payoff functions of the other players but also about their own payoff function affects the prospects of international cooperation using a simple game theoretic model it is shown how countries can use the veil of uncertainty to hide their distributional interests the arguments are based on a deviation from the common prior assumption which seems particularly questionable in a setting comprising various countries with different cultural and scientific backgrounds finally the model will prove useful to quantitatively and qualitatively illustrate the central role of model uncertainty in the negotiations of the first sulphur protocol signed to combat transboundary acidification

intertemporal emission permits trading under uncertainty and irreversibility this paper analyzes the effect of emission permit banking on clean technology investment and abatement under conditions where the stringency of the future cap is uncertain we examine the problem of heterogeneous firms minimizing the cost of intertemporal emission control in the presence of stochastic future pollution standards and emission permits that are tradable across firms and through time a firm can invest in clean capital an improved pollution abatement technology to reduce its abatement cost we consider two possibilities that investment is reversible or irreversible uncertainty is captured within a two period model only the current period cap is known we show that if banking is positive and marginal abatement costs are sufficiently convex there will be more abatement and investment in clean technology under uncertainty than there would be under certainty and no banking these results are at odds with the common belief that uncertainty on future environmental policy is a barrier to investment in clean capital moreover under uncertainty and irreversibility we find that there are cases where banking enables firms to invest more in clean capital

joint management of emission abatement and technological innovation for stock externalities we investigate how emission abatement and technological innovation provide different solutions to reduce pollutant emissions in the case of a stock externality emission abatement leads to a smooth and continuous adjustment of emissions conversely technological innovation has to be interpreted as an option on a less polluted environment and can justify the use of a pollution threshold above which it is optimal to start a research and development programme for a less polluting technology it is shown that technological innovation interferes with the traditional emission abatement approach the optimal abatement level is logically lowered once the less polluting technology is available nevertheless a temporary increase in emissions is optimal during the research and development period the usual pigouvian tax system proves to remain an efficient corrective instrument a numerical application to the greenhouse effect is provided

active learning and optimal climate policy this paper develops a climate economy model with uncertainty irreversibility and active learning whereas previous papers assume learning from one observation per period or experiment with control variables to gain additional information this paper considers active learning from investment in monitoring specifically in improved observations of the global mean temperature we find that the decision maker invests a significant amount of money in climate research far more than the current level in order to increase the rate of learning about climate change this helps the decision maker make improved decisions the level of uncertainty decreases more rapidly in the active learning model than in the passive learning model with only temperature observations as the uncertainty about climate change is smaller active learning reduces the optimal carbon tax the greater the risk the larger is the effect of learning the method proposed here is applicable to any dynamic control problem where the quality of monitoring is a choice variable for instance the precision at which we observe gdp unemployment or the quality of education

the irreversibility effect in environmental decisionmaking we provide a new more general definition for the irreversibility effect and demonstrate its relevance to problems involving environmental and other decisions under uncertainty we establish several analytical and numerical results that suggest both that the effect holds more widely than generally recognized and that an existing result epstein s theorem giving a sufficient condition for determining whether the effect holds can be applied more widely than previously indicated in particular to problems involving intertemporally nonseparable benefit functions we further show that a low elasticity of intertemporal substitution will however result in failure of the effect

transaction networks evidence from mobile money in kenya mobile money allows households in kenya to spread risk more efficiently in this paper we show that these efficiencies are achieved through deeper financial integration and expanded informal networks active networks are more geographically dispersed and support more reciprocal financial arrangements consistent with the reported reciprocity mobile money users report a higher share of transactions as being for credit and insurance purposes

financial inclusion and financial integrity aligned incentives summary the financial action task force embraces financial inclusion as complementary to anti money laundering and counter terrorist financing as it enhances transparency this support is based on the premise that the increased use of formal financial services leads to a reduction of usage of informal services we present evidence on eight african countries that both are not negatively associated moreover informal employment and cash preference reduce the inclination to use mobile financial services if an increase in transparency acts as disincentive to use formal services the alignment of financial inclusion and integrity will fail

the role of uncertainty and learning for the success of international climate agreements abstract transnational externalities e g transboundary pollution trade contagious diseases and terrorism warrant coordination and cooperation between governments but this proves often difficult one reason for the meager success is the public good character of many of these economic problems encouraging free riding another reason one might suspect is uncertainty surrounding most environmental problems and in particular climate change this provides often an excuse for remaining inactive paradoxically some recent papers have concluded just the opposite the veil of uncertainty can be conducive to the success of international environmental cooperation in this paper we explain why and under which conditions this can be true however we argue that those conditions are the exception rather than the rule most important we suggest a mechanism for those conditions where learning has a negative effect on the success of cooperation which removes this effect or even turns it into a positive effect our results apply beyond the specifics of climate change to similar problems where cooperation generates positive externalities

platform competition in two sided markets many if not most markets with network externalities are two sided to succeed platforms in industries such as software portals and media payment systems and the internet must get both sides of the market on board accordingly platforms devote much attention to their business model that is to how they court each side while making money overall this paper builds a model of platform competition with two sided markets it unveils the determinants of price allocation and end user surplus for different governance structures profit maximizing platforms and not for profit joint undertakings and compares the outcomes with those under an integrated monopolist and a ramsey planner jel l5 l82 l86 l96

optimal learning on climate change why climate skeptics should reduce emissions climate skeptics typically argue that the possibility that global warming is exogenous implies that we should not take additional action towards reducing emissions until we know what drives warming this paper however shows that even climate skeptics have an incentive to reduce emissions such a directional change generates information on the causes of global warming since the optimal policy depends upon these causes they are valuable to know although increasing emissions would also generate information that option is inferior due its irreversibility we show that optimality can even imply that climate skeptics should actually argue for lower emissions than believers

precautionary principle and the optimal timing of environmental policy under ambiguity i consider a problem in environmental policy design in which i focus on stock pollutants in particular i consider stock pollutants that cause severe damage on the environment and do not depreciate at all once they are released into the atmosphere and the ocean the purposes of this paper are 1 to provide an economic foundation for environmental policies based on the precautionary principle and the 1992 rio declaration on environment and development and 2 to show that this optimal timing rule has a reservation property furthermore i analyze the effect of an increase in ambiguity on the optimal timing of adopting some environmental policy and show that an increase in ambiguity decreases the optimal timing of adopting the environmental policy

banking the poor via savings accounts evidence from a field experiment abstract in a setting with low penetration of bank accounts i randomly gave access to bank accounts with zero fees at local bank branches to a large sample of female household heads in nepal the zero fees and physical proximity of the bank led to high take up and usage rates compared to similar studies in other settings however impact on income aggregate expenditures and assets are too imprecisely estimated to draw a conclusion i do find reallocation of expenditures across categories e g more spending on education and meat and fish and less on health and dowries and higher ability to cope with shocks on qualitative outcomes i find households report that their overall financial situation has improved the lack of a clear story on mechanisms yet strong result on aggregate self perception of financial wellbeing is consistent with access to quality savings accounts leading to household improvements via multiple mechanisms

cross country variation in household access to financial services abstract this paper presents estimates for more than 160 countries of the fraction of the adult population using formal financial intermediaries the estimates are constructed by combining information on account numbers at banks and microfinance institutions together with banking depth and gdp data with estimates from household surveys for a smaller set of countries an illustrative application of the data compares them with information on poverty there is a correlation but it is not clearly causal

optimal timing problems in environmental economics abstract because of the uncertainties and irreversibilities that are often inherent in environmental degradation its prevention and its economic consequences environmental policy design can involve important problems of timing i use a simple two period model to illustrate these optimal timing problems and their implications for environmental policy i then lay out and solve a continuous time model of policy adoption in which the policy itself entails sunk costs and environmental damage is irreversible the model generalizes earlier work in that it includes two stochastic state variables one captures uncertainty over environmental change and the other captures uncertainty over the social costs of environmental damage solutions of the model are used to show the implications of these two types of uncertainty for the timing of policy adoption

uncertainty learning and international environmental policy coordination in this paper we construct a simple model of global warming which captures a number of key features of the global warming problem i environmental damages are related to the stock of greenhouse gases in the atmosphere ii the global commons nature of the problem means that these are strategic interactions between the emissions policies of the governments of individual nation states iii there is uncertainty about the extent of the future damages that will be incurred by each country from any given level of concentration of greenhouse gases but there is the possibility that at a future date better information about the true extent of environmental damages may become available an important aspect of the problem is the extent to which damages in different countries may be correlated in the first part of the paper we consider a simple model with two symmetric countries and show that the value of perfect information is an increasing function of the correlation between damages in the two countries in both the cooperative and non cooperative equilibria however while the value of perfect information is always non negative in the cooperative equilibrium in the non cooperative equilibrium there is a critical value of the correlation coefficient below which the value of perfect information will be negative in the second part of the paper we construct an empirical model of global warming distinguishing between oecd and non oecd countries and show that in the non cooperative equilibrium the value of perfect information for oecd countries is negative when the correlation coefficient between environmental damages for oecd and non oecd countries is negative the implications of these results for international agreements are discussed

fundamental irreversibilities in stock externalities abstract this paper concerns the irreversibility effect in stock externalities in an environment of uncertainty with learning taking place one may wish to under emit today to avoid potential environmental irreversibilities alternatively one may wish to under invest in pollution control capital avoiding investments in sunk capital that turn out to be wasted the paper develops theoretical results on the tension between these two effects and separates risk aversion from the irreversibility effect the paper also presents a simple example in climate change policy

environmental consciousness and moral hazard in international agreements to protect the environment abstract a group of countries that can potentially commit to cooperation to protect the environment are identified as environmentally conscious countries conditions are examined under which they can provide self financing side payments too a second group of less environmentally conscious countries so that the two groups form a global or partial stable coalition that agrees to reduce emissions a mechanism that detects cheating is also developed in order to induce the desired emissions even when the emissions level of an individual country cannot be observed by the rest of the participating countries

looking for a guide to protect the environment the development of the precautionary principle abstract if the precautionary principle is to become the guide of the international community for environmental protection policies an economic interpretation of the principle is in order the analysis of case studies and a survey of the recent decision theoretic literature show the lack of a fully satisfactory economic model more generally various theoretical and empirical results show that the principle cannot be assumed to apply a priori though it has been proposed by international treaties as a rule of thumb for situations of scientific uncertainty the precautionary principle could actually be inefficient

regulatory actions under adjustment costs and the resolution of scientific uncertainty food system regulators often decide whether to ban existing practices or approve new technologies without conclusive scientific evidence on possible damage and knowing that resolution is likely in the future in a model with three decision points and stochastic resolution of uncertainty we study interactions between expected losses due to regulation and information availability when a regulator is deciding on an early reversible ban and on a later reversible ban adjustment costs create inertia concerning intermediate signals such that earlier decisions are not overturned and also a bias against imposing an early ban the prospect of more later stage information can increase or decrease the incentive to ban early but research decreases the incentive to ban early

the digital provide information technology market performance and welfare in the south indian fisheries sector when information is limited or costly agents are unable to engage in optimal arbitrage excess price dispersion across markets can arise and goods may not be allocated efficiently in this setting information technologies may improve market performance and increase welfare between 1997 and 2001 mobile phone service was introduced throughout kerala a state in india with a large fishing industry using microlevel survey data we show that the adoption of mobile phones by fishermen and wholesalers was associated with a dramatic reduction in price dispersion the complete elimination of waste and near perfect adherence to the law of one price both consumer and producer welfare increased

regulation with anticipated learning about environmental damages a regulator anticipates learning about the relation between environmental stocks and economic damages for a model with linear quadratic abatement costs and environmental damages and a general learning process we show analytically that anticipated learning decreases the optimal level of abatement at a given information set if learning causes the regulator to eventually decide that damages are higher than previously thought learning eventually increases abatement learning also favors the use of taxes rather than quotas using a model that is calibrated to describe the problem of global warming we show numerically that anticipated learning causes a significant reduction in first period abatement and a small increase in the preference for taxes rather than quotas even if the regulator s initial priors about environmental damages are much too optimistic he is able to learn quickly enough to keep the expected stock trajectory near the optimal trajectory

climate change mitigation and adaptation with uncertainty and learning one of the major issues in climate change policy is how to deal with the considerable uncertainty that surrounds many of the elements some of these uncertainties will be resolved through the process of further research this process of learning raises a crucial timing question should society delay taking action in anticipation of obtaining better information or should it accelerate action because we might learn that climate change is much more serious than expected much of the analysis to date has focussed on the case where the actions available to society are just the mitigation of emissions and where there is little or no role for learning we extend the analysis to allow for both mitigation and adaptation we show that including adaptation weakens the effect of the irreversibility constraint and so for this model makes it more likely that the prospect of future learning should lead to less action now to deal with climate change we review the empirical literature on climate change policy with uncertainty learning and irreversibility and show that to date the effects on current policy are rather small though this may reflect the particular choice of models employed

irreversible abatement investment under cost uncertainties tradable emission permits and emissions charges abstract a major concern with tradable emission permits is that stochastic permit prices may reduce a firm s incentive to invest in abatement capital or technologies relative to other policies such as a fixed emissions charge however under efficient permit trading the permit price uncertainty is caused by abatement cost uncertainties which affect investment under both permit and charge policies we develop a rational expectations general equilibrium model of permit trading and irreversible abatement investment to show how cost uncertainties affect investment under permits we compare the resulting investment incentive with that under charges after controlling for the assumption that random shocks affect the abatement cost linearly we find that firms investment incentive decreases in cost uncertainties but more so under emissions charges than under permits therefore tradable permits in fact may help maintain firms investment incentive under uncertainty

finance and growth in africa the broken link abstract while bank liabilities in sub saharan africa are found to follow but not lead economic growth the link between bank credit and growth is altogether absent

correlated equilibrium as an expression of bayesian rationality if it is common knowledge that the players in a game are bayesian utility maximizers who treat uncertainty about other players actions like any other uncertainty then the outcome is necessarily a correlated equilibrium random strategies appear as an expression of each player s uncertainty about what the others will do not as the result of willful randomization use is made of the common prior assumption according to which differences in probability assessments by different individuals are due to the different information that they have where information may be interpreted broadly to include experience upbringing and genetic makeup copyright 1987 by the econometric society

risk averse mitigation decisions in an unpredictable climate system risk aversion plays a central role in the decisions made in the face of uncertainties and climate change mitigation should be no exception however the interlinkage of risk aversion and climate change uncertainties has hardly been investigated numerically in part because of the computational difficulties of stochastic optimization in this paper we apply the numerical techniques of stochastic optimization to the economic modeling of climate change with the aim of modeling the decision preferences of a risk conscious agent in the face of unpredictable climate change the model underlines the critical role played by the risk aversion parameter in determining the effects of uncertainties on mitigation not only in level but also in sign

providing global public goods under uncertainty abstract we study how uncertainty and risk aversion affect international agreements to supply global public goods we consider a benchmark model with homogeneous countries and linear payoffs when countries directly contribute to a public good uncertainty tends to lower signatories efforts but may increase participation despite risk aversion uncertainty may improve welfare in contrast when countries try to reduce a global public bad uncertainty tends to increase signatories efforts and decrease participation in that case an ex ante reduction of uncertainty may have a large positive multiplier effect on welfare

reaching out access to and use of banking services across countries the authors 1 present new indicators of banking sector penetration across 99 countries based on a survey of bank regulatory authorities 2 show that these indicators predict household and firm use of banking services 3 explore the association between the outreach indicators and measures of financial institutional and infrastructure development across countries and 4 relate these banking outreach indicators to measures of firms financing constraints in particular they find that greater outreach is correlated with standard measures of financial development as well as with economic activity controlling for these factors the authors find that better communication and transport infrastructure and better governance are also associated with greater outreach government ownership of financial institutions translates into lower access while more concentrated banking systems are associated with greater outreach finally firms in countries with higher branch and atm penetration and higher use of loan services report lower financing obstacles thus linking banking sector outreach to the alleviation of firms financing constraints

mobile money in tanzania in developing countries mobile telecom networks have emerged as major providers of financial services bypassing the sparse retail networks of traditional banks we analyze a large individual level data set of mobile money transactions in tanzania to provide evidence of the impact of mobile money on alleviating financial exclusion in developing countries we identify three types of transactions i money transfers to others ii short distance money self transportation and iii money storage for short to medium periods of time we utilize a natural experiment of an unanticipated increase in transaction fees to identify the demand for these transactions using the demand estimates we find that the willingness to pay to avoid walking with cash an extra kilometer short distance self transportation and to avoid storing money at home money storage for an extra day are 1 25 and 0 8 of an average transaction respectively which demonstrates that mobile money ameliorates significant amounts of crime

learning and stock effects in environmental regulation the case of greenhouse gas emissions abstract this paper concerns the optimal regulation of greenhouse gases that lead to global climate change in particular we focus on uncertainty and learning which over time resolves uncertainty we present an empirical stochastic model of climate economy interactions and present results on the tension between postponing control until more is known vs acting now before irreversible climate change takes place uncertainty in our model is in the damage caused by global warming the results suggest that a temporary carbon tax may dominate a permanent one because a temporary tax may induce increased flexibility

the effectiveness of quantitative easing evidence from japan abstract this study contributes to current research on quantitative easing we provide a novel analysis of the quantitative easing effectiveness as an unconventional monetary policy tool in japan over the last two decades the paper advances current research on quantitative easing by exploring quantitative easing through the prism of the monetary transmission mechanism we examine the response of japanese regional banks to the quantitative easing operations conducted by the bank of japan from the early 2000s till 2015 the analysis is performed within the framework of the bank lending channel under the unconventional monetary policy strategies we find that small sized regional banks underline the significant positive effect of quantitative easing on gross domestic product and inflation that works through the securities holdings and leverage preferences monetary authorities should pay particular attention to policies for such banks and banks with a high level of non performing loans deposit growth after a quantitative easing shock is only present in large sized banks with low npls holdings

designing climate mitigation policy this us paper provides an exhaustive review of critical issues in the design of climate mitigation policy by pulling together key findings and controversies from diverse literatures on mitigation costs damage valuation policy instrument choice technological innovation and international climate policy the authors begin with the broadest issue of how high assessments suggest the near and medium term price on greenhouse gases would need to be both under cost effective stabilization of global climate and under net benefit maximization or pigouvian emissions pricing the remainder of the paper focuses on the appropriate scope of regulation issues in policy instrument choice complementary technology policy and international policy architectures

the economic consequences of social network structure we survey the literature on the economic consequences of the structure of social networks we develop a taxonomy of macro and micro characteristics of social interaction networks and discuss both the theoretical and empirical findings concerning the role of those characteristics in determining learning diffusion decisions and resulting behaviors we also discuss the challenges of accounting for the endogeneity of networks in assessing the relationship between the patterns of interactions and behaviors

optimal investment in clean production capacity for the mitigation of long term pollution threats one must consider that both the process of environmental degradation and the switchover to new and cleaner technologies are dynamic we develop a model of a uniform good that can be produced by either a polluting technology or a clean one the latter is more expensive and requires investment in capacity we derive the socially optimal pollution stock accumulation and creation of nonpolluting production capacity weighing the tradeoffs among consumption investment and djustment costs and environmental damages we consider the effects of changes in the pollution decay rate the capacity depreciation rate and the initial state of the environment on both the steady state and the transition period the optimal transition path looks quite different with a clean or dirty initial environment with the former investment is slow and the price of pollution may overshoot the long run optimum before converging with the latter capacity may overshoot

the unbanked evidence from indonesia to analyze the prospects for expanding financial access to the poor bank professionals assessed 1 438 households in six provinces in indonesia to judge their creditworthiness about 40 percent of poor households were judged creditworthy according to the criteria of indonesia s largest microfinance bank but fewer than 10 percent had recently borrowed from a micro bank or formal lender possessing collateral appeared as a minor determinant of creditworthiness in keeping with microfinance innovations although these households were judged able to service loans reliably most desired small loans calculations show that the bank given its current fee structure and banking practices will lose money when lending at the scales desired so while innovations have helped to extend financial access it remains difficult to lend in small amounts and cover costs

information and the concept of option value this paper examines the arrow fisher henry concept of option value and analyzes its properties including its relationship to the value of information and the effects of increasing uncertainty about the future consequences of irreversible development it is shown that this option value is distinct from but bounded by the value of information in the overall decision problem also it is distinct from a concept of option value that appears in b s bernanke quart j econom 98 85 106 1983 however when there is a continuum of development levels rather than a binary choice between full development and no development some of these conclusions need to be modified

quantitative easing and related capital flows into brazil measuring its effects and transmission channels through a rigorous counterfactual evaluation abstract we show that unconventional monetary policy in the united states appears to influence capital inflows to brazil and through this channel its overall economic outlook and financial stability in particular quantitative easing leads to capital inflows exchange rate appreciation stock market price increases credit growth and expansion of domestic activity related to consumption such effects are significant when considering both parameter uncertainty and a new significance test for abnormal behavior according to a new channel identification method proposed in the paper capital inflow is the only domestic propagation channel that systematically accounts for the estimated effects across variables and samples results are robust across a wide range of policy counterfactuals regime break assumptions testing procedures and model specifications

uncertainty learning and heterogeneity in international environmental agreements this paper concerns the formation of international environmental agreements under uncertainty about environmental damage with different models of learning complete learning partial learning or no learning the results of the existing literature are generally pessimistic the possibility of either complete or partial learning generally reduces the level of global welfare that can be achieved from forming an iea relative to no learning that literature regards uncertainty as a parameter common to all countries so that countries are identical ex ante as well as ex post in this paper we extend the literature to the case where there is no correlation between damage costs across countries each country is uncertain about a particular parameter in our case the benefit cost ratio drawn from a common distribution but ex post each country s realized parameter value is independently drawn consequently while countries remain identical ex ante they may be heterogeneous ex post we show that this change reinforces the negative conclusions about the effects of partial learning on international environmental agreements but under certain conditions moderates the negative conclusions about the effects of complete learning

financial inclusion gender dimension and economic impact on poor households summary we examine the question in the context of gender dimension what is the evidence of the impact of the financial inclusion programs on poor households represented by women relative to that represented by men by constructing a good counterfactual and comparison group we employ the difference in difference estimator approach with panel least squares and generalized methods of moments using standard errors for a robust analysis we notice that income growth cagr net of inflation effect was 8 40 for women as against 3 97 for men indicating that the gender of participating poor undoubtedly affects the outcomes of these programs

addressing global environmental externalities transaction costs considerations is there a way to understand why some global environmental externalities are addressed effectively whereas others are not the transaction costs of defining the property rights to mitigation benefits and costs is a useful framework for such analysis this approach views international cooperation as a contractual process among country leaders to assign those property rights leaders cooperate when it serves domestic interests to do so the demand for property rights comes from those who value and stand to gain from multilateral action property rights are supplied by international agreements that specify resource access and use assign costs and benefits including outlining the size and duration of compensating transfer payments and determining who will pay and who will receive them four factors raise the transaction costs of assigning property rights i scientific uncertainty regarding mitigation benefits and costs ii varying preferences and perceptions across heterogeneous populations iii asymmetric information and iv the extent of compliance and new entry these factors are used to examine the role of transaction costs in the establishment and allocation of property rights to provide globally valued national parks implement the convention on the international trade in endangered species of wild fauna and flora execute the montreal protocol to manage emissions that damage the stratospheric ozone layer set limits on harvest of highly migratory ocean fish stocks and control greenhouse gas emissions jel d23 p14 q22 q51 q54 q58

optimal environmental management in the presence of irreversibilities abstract we consider an environment of a fixed size that can be converted to another use this conversion can be made in steps but it is irreversible the future benefits per unit from the original use and from the alternative use follow a diffusion process for a fairly general case we show that the value function must be the unique viscosity solution to the associated hamilton jacobi bellman equation we also exhibit several properties of the solution for the case of constant relative risk aversion between 0 and 1 and a log linear diffusion for the benefits journal of economic literature classification numbers c61 d90 q30

mobile money financial inclusion and development a review with reference to african experience we survey literature on mobile money and its contribution in promoting financial inclusion and development with a focus on sub saharan africa we use taxonomic descriptive and analytical methods to evaluate the state of knowledge in the area we analyse how mobile technology in general may contribute to economic development and financial inclusion in theory and practise we explain the mechanics of mobile money using kenya s m pesa as a canonical example and consider whether the literature has fully established the potential economic impact of mobile money especially its contribution to financial inclusion we also consider market structure pricing and regulatory implications of mobile money we conclude by highlighting issues that require further investigation the take up of mobile money mobile money and financial inclusion substitutability between mobile money and conventional finance and regulatory structures for institutions providing mobile money services

revocability and reversibility in societal decision making abstract reversibility and irreversibility are poorly defined in the decision making literature defining reversibility as the ability to maintain and to restore the functional performance of a system is consistent with thermodynamics specification of its crucial terms is case dependent reversibility is coming in degrees from flexibility over rigidity to preclusion with irreversibility as an absolute end further substantiating reversibility considers three variables duration of impacts revoking costs and substitutability substitutability depends on weights assigned to the strict identity or to the functional performance of something valued for given degrees of substitutability revocability of an action is measurable in time dependent revoking costs together with future time and doubt reversibility sets a three dimensional context for societal decision making revealing domes of expanding complexity cost benefit analysis is a useful decision tool at lower complexity but falters at high complexity because there prevail non monetary trade offs a revival and proper use of the concept reversibility are recommended for improved dialog on major societal issues with climate change outstanding as the case where reversibility could turn into absolute irreversibility also shown is the correspondence between reversibility and ecological concepts like resilience lock in tipping points and others

global warming endogenous risk and irreversibility this paper develops two period analytical and numerical models to study the question given a stock of greenhouse gases that poses a risk of future damages of unknown magnitude and the possibility of learning about damages how do sunk abatement capital and a nondegradable stock of greenhouse gases affect optimal first period investment we show that both affect investment the former negatively and the latter positively additionally endogenous risk the risk of damages dependent on the stock of gases results in an increase in optimal investment for any level of capital sunkness or greenhouse gas degradability quantitatively the effect of sunk capital is stronger than the effect of greenhouse gas irreversibility or that of endogenous risk

banking services for everyone barriers to bank access and use around the world using information from 193 banks in 58 countries the authors develop and analyze indicators of physical access affordability and eligibility barriers to deposit loan and payment services they find substantial cross country variation in barriers to banking and show that in many countries these barriers can potentially exclude a significant share of the population from using banking services correlations with bank and country level variables show that bank size and the availability of physical infrastructure are the most robust predictors of barriers further the authors find evidence that in more competitive open and transparent economies and in countries with better contractual and informational frameworks banks impose lower barriers finally though foreign banks seem to charge higher fees than other banks in foreign dominated banking systems fees are lower and it is easier to open bank accounts and to apply for loans on the other hand in systems that are predominantly government owned customers pay lower fees but also face greater restrictions in terms of where to apply for loans and how long it takes to have applications processed these findings have important implications for policy reforms to broaden access

can uncertainty alleviate the commons problem global commons problems such as climate change are often affected by severe uncertainty the paper examines the effect of uncertainty on pollution emissions and welfare in a strategic context we find that emissions are always lower under uncertainty than under certainty reflecting risk reducing considerations we show that uncertainty can have a net positive impact on the welfare of risk averse polluters we extend the analysis to increases in risk increases in risk aversion and to risk heterogeneity jel d81 c72 q54 h23

communicating trade offs amid controversial science decision support for climate policy abstract the paper considers the decision that arises in climate policy where there is expert disagreement about the correct scientific model and where a group of stakeholders needs to agree on a common policy target policy choice is posed as a decision under knightian uncertainty where decision makers lack grounds for assigning a particular probability distribution across contending forecasting models the decision is then framed as one of balancing two competing objectives that plausibly align with the dominant concern of stakeholders from each side in the policy debate a decision criterion is proposed to identify options for compromise that balance these objectives in different ways the criterion spans three standard non bayesian decision criteria policies generated by the criterion are combined with visual tools to communicate what s at stake in an environmental policy decision in which stakeholders disagree both about scientific models and about the relative importance of risks to the environment versus risks to economic growth the approach summarizes information that could be useful to policy makers tasked with negotiating a compromise the framework is applied to climate policy using dice 2007 nordhaus 2008 the results highlight a basic asymmetry between the mistake of doing too little and that of doing too much that suggests a strong argument for avoiding the current status quo of global inaction

scientific progress and irreversibility an economic interpretation of the precautionary principle abstract we consider the problem of the optimal use of a good whose consumption can produce damages in the future scientific progress is made over time that provides information on the distribution of the intensity of damages we show that this progress induces earlier prevention effort only if prudence is larger than twice absolute risk aversion this paper thus identifies the class of quite restrictive but plausible conditions such that scientific uncertainties justify an immediate reduction of the consumption of a potentially toxic substance

strategic information acquisition and the mitigation of global warming abstract we consider the strategic role of uncertainty and information acquisition for the mitigation of global warming before the countries decide on their contribution to a mitigation of global warming they may invest in information about the country specific benefit of reductions of the emissions of greenhouse gases we show that information acquisition has a substantial strategic value countries may prefer not to learn their benefit of climate protection even if information acquisition does not involve a direct cost this strategic information choice may further decrease the efficiency of the public good provision

specifications of social welfare in economic studies of climate policy overview of criteria and related policy insights an important assumption in economic studies of climate policy is the social welfare function this paper shows that applying distinct decision or social welfare criteria can result in different optimal policies of climate control notably if climate change impacts are uncertain first decision criteria in current climate economic studies are reviewed next the most important alternatives are discussed including their mathematical formalization and incorporation in economy climate models most of these alternative criteria suggest more stringent climate policies to be optimal than the standard discounted utilitarianism approach however several important welfare criteria have not or hardly seen any application in the economic analysis of climate policy we conclude that there is clear need for systematic research on this theme for which the current review provides a solid basis

taking one for the team is collective action more responsive to ecological change debate persists around the timing of risk reduction strategies for large scale ecological change for three reasons risks are difficult to predict they involve irreversibilities and they impact multiple jurisdictions the combination of these three factors creates a general class of filterable spatial dynamic externalities fsde in which one person s risk reduction investments reduce or filter undesirable events experienced by others and underestimates the option value placed on being able to respond to new information about the consequences of ecological change by focusing on the optimal intervention decision we illustrate how and when the opposing forces created by an fsde will lead to a divergence in private and collective risk reduction strategies we use bioinvasions as our motivating example the bioinvasion first hits one jurisdiction and that jurisdiction s risk reduction investment reduces the risk faced by all other jurisdiction we find that efforts to internalize the full benefits of risk reduction investments may have unintended consequences on the responsiveness of environmental policy there is a social welfare gain from asking the first jurisdiction to delay a risk reduction investment to internalize the option values of all at risk jurisdictions

the effectiveness of alternative monetary policy tools in a zero lower bound environment this paper reviews alternative options for monetary policy when the shortterm interest rate is at the zero lower bound and develops new empirical estimates of the effects of the maturity structure of publicly held debt on the term structure of interest rates we use a model of risk averse arbitrageurs to develop measures of how the maturity structure of debt held by the public might affect the pricing of level slope and curvature term structure risk we find that these treasury factors historically were quite helpful for predicting both yields and excess returns over 1990 2007 the historical correlations are consistent with the claim that if in december 2006 the fed were to have sold off all its treasury holdings of less than 1 year maturity about 400 billion and use the proceeds to retire treasury debt from the long end this might have resulted in a 14 basis point drop in the 10 year rate and an 11 basis point increase in the 6 month rate we also develop a description of how the dynamic behavior of the term structure of interest rates changed after hitting the zero lower bound in 2009 our estimates imply that at the zero lower bound such a maturity swap would have the same effects as buying 400 billion in long term maturities outright with newly created reserves and could reduce the 10 year rate by 13 basis points without raising short term yields

tying odysseus to the mast evidence from a commitment savings product in the philippines we designed a commitment savings product for a philippine bank and implemented it using a randomized control methodology the savings product was intended for individuals who want to commit now to restrict access to their savings and who were sophisticated enough to engage in such a mechanism we conducted a baseline survey on 1777 existing or former clients of a bank one month later we offered the commitment product to a randomly chosen subset of 710 clients 202 28 4 percent accepted the offer and opened the account in the baseline survey we asked hypothetical time discounting questions women who exhibited a lower discount rate for future relative to current trade offs and hence potentially have a preference for commitment were indeed significantly more likely to open the commitment savings account after twelve months average savings balances increased by 81 percentage points for those clients assigned to the treatment group relative to those assigned to the control group we conclude that the savings response represents a lasting change in savings and not merely a short term response to a new product

international macroeconomic policy coordination when policymakers do not agree on the true model the authors relax the assumption of the literature on international coordination that policymakers know the true model t wo countries will still be able to agree on a cooperative policy pack age that each believes will improve the objective function relative t o the nash noncooperative solution however the bargaining solution may move the target variables in the wrong direction these points ar e illustrated with monetary and fiscal multipliers taken from simulat ions of ten leading econometric models out of 1 000 possible combina tions of models that could represent u s beliefs non u s beliefs and the true model monetary coordination improves u s welfare in on ly 546 cases copyright 1988 by american economic association

agricultural decisions after relaxing credit and risk constraints the investment decisions of small scale farmers in developing countries are conditioned by their financial environment binding credit market constraints and incomplete insurance can limit investment in activities with high expected profits we conducted several experiments in northern ghana in which farmers were randomly assigned to receive cash grants grants of or opportunities to purchase rainfall index insurance or a combination of the two demand for index insurance is strong and insurance leads to significantly larger agricultural investment and riskier production choices in agriculture the binding constraint to farmer investment is uninsured risk when provided with insurance against the primary catastrophic risk they face farmers are able to find resources to increase expenditure on their farms demand for insurance in subsequent years is strongly increasing with the farmer s own receipt of insurance payouts with the receipt of payouts by others in the farmer s social network and with recent poor rain in the village both investment patterns and the demand for index insurance are consistent with the presence of important basis risk associated with the index insurance imperfect trust that promised

uncertainty learning and international environmental agreements the role of risk aversion this paper analyses the formation of international environmental agreements ieas under uncertainty learning and risk aversion it bridges two strands of the iea literature i the role of learning when countries are risk neutral ii the role of risk aversion under no learning combining learning and risk aversion seems appropriate as the uncertainties surrounding many international environmental problems are large often highly correlated e g climate change but are gradually reduced over time through learning the paper analyses three scenarios of learning a key finding is that risk aversion can change the ranking of these three scenarios of learning in terms of welfare and membership in particular the negative conclusion about the role of learning in a strategic context under risk neutrality is qualified when countries are significantly risk averse then it pays them to wait until uncertainties have been largely resolved before joining an iea this may suggest why it has been so difficult to reach an effective climate change agreement

are remittances insurance evidence from rainfall shocks in the philippines several facts motivate this study first life in developing countries is prone to many kinds of risk such as crop and income loss due to natural disasters weather insect infestations and fire and civil conflict second international migration and remittance flows are substantial and growing between 1965 and 2000 individuals living outside their country of birth grew from 2 2 to 2 9 percent of the world population totaling 175 million people in 2000 the remittances that these migrants send to their countries of origin are an important but poorly understood type of international financial flow this article examines a mechanism for coping with shocks ex post on which previous micro level studies have not focused remittances from family members overseas at the international level it is commonly posited that remittance flows from overseas buffer economic shocks in migrants home countries but there have been relatively few empirical tests of this claim with micro level household data related research on the role of domestic migration in pooling risk within extended families includes lucas and stark 1985 rosenzweig and stark 1989 and paulson 2000

modeling the forms of international cooperation distribution versus information the problems of distribution and information impede international cooperation they arise when actors select how they will cooperate an exploration of the interaction between these problems using a limited information model of cooperation leads to six conclusions first leadership solutions to coordination problems always exist but leadership here is very different from hegemonic provision of public goods second actors can cooperate in the face of anarchy even without a shadow of the future third diffuse reciprocal strategies arise naturally in coordination problems fourth norms and institutions are intertwined within successful cooperation fifth the form of cooperation on an issue varies with the relative importance of distribution and information finally and most important distributional and informational problems interfere with each other arrangements to cooperate can successfully address one but not both of these problems

piercing the veil of uncertainty in transboundary pollution agreements this paper addresses the question of how uncertainty in costs and benefits affects the difficulty of reaching a voluntary agreement among sovereign states a measure of difficulty is constructed related to side payments necessary to make an agreement a pareto improving move using a simple model it is shown that uncertainty actually makes agreement easier

event studies in economics and finance the event study is an important research tool in economics and finance the goal of an event study is to measure the effects of an economic event on the value of firms event study methods exploit the fact that given rationality in the marketplace the effects of an event will be reflected immediately in security prices thus the impact can be measured by examining security prices surrounding the event in this paper event study methods are described including some of the potential complications an example is included to illustrate the approach

finance and the sources of growth the authors evaluate whether the level of development in the banking sector exerts a causal impact on economic growth and its sources total factor productivity growth physical capital accumulation and private saving they use 1 a pure cross country instrumental variable estimator to extract the exogenous component of banking development and 2 a new panel technique that controls for country specific effects and endogeneity they find that banks do exert a large causal impact on total factor productivity growth which feeds through to overall gdp gross domestic product growth the long run links between banking development and both capital growth and private savings are more tenuous

financial development and economic growth views and agenda this critique argues that the preponderance of theoretical reasoning and empirical evidence suggests a positive first order relationship between financial development and economic growth the body of work would push even most skeptics toward the belief that the development of financial markets and institutions is a critical and inextricable part of the growth process and away from the view that the financial system is an inconsequential sideshow responding passively to economic growth many gaps remain however and the paper highlights areas in acute need of additional research

risk sharing and transactions costs evidence from kenya s mobile money revolution we explore the impact of reduced transaction costs on risk sharing by estimating the effects of a mobile money innovation on consumption in our panel sample adoption of the innovation increased from 43 to 70 percent we find that while shocks reduce consumption by 7 percent for nonusers the consumption of user households is unaffected the mechanisms underlying these consumption effects are increases in remittances received and the diversity of senders we report robustness checks supporting these results and use the four fold expansion of the mobile money agent network as a source of exogenous variation in access to the innovation jel e42 g22 o16 o17 z13 in developing countries informal networks provide an important means by which individuals and households share risk though the insurance they provide is often incomplete economists have proposed a number of reasons for this incompleteness including information asymmetries which manifest in problems of moral hazard and limited commitment both of which induce positive correlations between realized income and consumption in this article we emphasize a complementary source of incompleteness transaction costs literally the costs of transferring resources between individuals we test the impact of transaction costs on risk sharing by analyzing data from a large panel household survey that we designed and administered in kenya over a three year period to capture the expansion of mobile money this financial innovation has allowed individuals to transfer purchasing power by simple short messaging service sms technology and has dramatically reduced the cost of sending money across large distances mobile money is a recent innovation in developing economies one of the first and most successful examples to date is kenya s m pesa 1 in just four years after its