risk sharing and contagion in networks we investigate the socially optimal design of financial networks that allows to tackle the trade off between risk sharing and contagion we identify conditions on the shock distribution under which full integration or maximal segmentation is optimal we also show that under different conditions the optimal network displays different levels of strength of linkages to other firms or intermediate degrees of segmentation in the latter case the individual and social incentives to establish linkages are not necessarily aligned when firms face heterogeneous distributions of risks they should optimally form linkages only with firms facing risks of the same kind

explaining the border effect the role of exchange rate variability shipping costs and geography this paper exploits a three dimensional panel data set of prices on 27 traded goods over 88 quarters across 96 cities in the us and japan we show that a simple average of good level real exchange rates tracks the nominal exchange rate well suggesting strong evidence of sticky prices focusing on dispersion in prices between city pairs we find that crossing the us japan border is equivalent to adding as much as 43 000 trillion miles to the cross country volatility of relative prices we turn next to economic explanations for this so called border effect and to its dynamics distance unit shipping costs and exchange rate variability collectively explain a substantial portion of the observed international market segmentation relative wage variability on the other hand has little independent impact on segmentation 2001 elsevier science b v all rights reserved

a theory of input output architecture individual producers exhibit enormous heterogeneity in many dimensions this paper develops a theory in which the network structure of production who buys inputs from whom forms endogenously entrepreneurs produce using labor and exactly one intermediate input the key decision is which other entrepreneur s good to use as an input their choices collectively determine the economy s equilibrium input output structure generating large differences in size and shaping both individual and aggregate productivity when the elasticity of output to intermediate inputs in production is high star suppliers emerge endogenously this raises aggregate productivity as in equilibrium more supply chains are routed through higher productivity techniques

merger policy with merger choice we analyze the optimal policy of an antitrust authority towards horizontal mergers when merger proposals are endogenous and firms choose which of several mutually exclusive mergers to propose in our model the optimal policy of an antitrust authority that seeks to maximize expected consumer surplus imposes a tougher standard on larger mergers i e those involving firms with a larger pre merger market share or equivalently leading to a larger naively computed post merger herfindahl index the optimal policy is a response to a bias in firms proposal incentives firms always propose a larger merger when it is better for consumers than a smaller one but sometimes will propose the larger one even when it is worse for consumers

total factor carbon emission performance of the chinese transportation industry a bootstrapped non radial malmquist index analysis this paper proposes a non radial malmquist co2 emission performance index nmcpi for measuring dynamic changes in total factor co2 emission performance over time this index enables the consideration of non radial slacks in the conventional malmquist co2 emission index mcpi the nmcpi is calculated based on a non radial directional distance function derived by several data envelopment analysis dea models furthermore nmcpi could be decomposed into an efficiency change ec index and technological change tc index a bootstrapping approach is conducted to introduce statistical inferences into the nmcpi and its decompositions based on the proposed indices the dynamic co2 emission performance change and its decompositions of the chinese regional transportation industry from 2002 to 2010 are investigated the empirical results demonstrate that the total factor carbon emission performance of the transportation industry as a whole decreased by 32 8 over the period and this reduction was primarily caused by technological decline

will digital technologies transform agriculture in developing countries mobile phones and the internet have significantly affected practically all sectors of the economy and agriculture is no exception building on a recent world bank flagship report this article introduces a concise framework for describing the main benefits from new information and communication technologies they promote greater inclusion in the broader economy raise efficiency by complementing other production factors and foster innovation by dramatically reducing transaction costs the article reviews the recent literature on corresponding technology impacts in the rural sector in developing countries digital technologies overcome information problems that hinder market access for many small scale farmers increase knowledge through new ways of providing extension services and they provide novel ways for improving agricultural supply chain management while there are many promising examples of positive impacts on rural livelihoods or digital dividends these have often not scaled up to the extent expected the main reason is that technology can always only address some but not all of the barriers faced by farmers in poorer countries

sulfur dioxide control by electric utilities what are the gains from trade title iv of the 1990 clean air act amendments caaa established a market for transferable sulfur dioxide so2 emission allowances among electric utilities this market offers firms facing high marginal abatement costs the opportunity to purchase the right to emit so2 from firms with lower costs and this is expected to yield cost savings compared to a command and control approach to environmental regulation this paper uses econometrically estimated marginal abatement cost functions for power plants affected by title iv of the caaa to evaluate the performance of the so2 allowance market specifically we investigate whether the much heralded fall in the cost of abating so2 compared to original estimates can be attributed to allowance trading we demonstrate that for plants that use low sulfur coal to reduce so2 emissions technical change and the fall in prices of low sulfur coal have lowered marginal abatement cost curves by over 50 percent since 1985 the flexibility to take advantage of these chan

productivity growth and biased technological change in hydroelectric dams abstract this paper analyses productivity growth and the nature of technical change in a sample of portuguese hydroelectric generating plants over the period 2001 to 2008 in a first step we employ the luenberger productivity indicator to estimate and decompose productivity change a malmquist productivity index is also used for a comparative purpose the results paint a picture of mixed productivity performance in the portuguese energy sector the first decomposition underlines that in average the productivity variation is explained by the technological change then in a second step we analyse the nature of this technical change by using the recent concept of parallel neutrality briec et al 2006 we observe a global shift in the best practice frontier as well as in the evidence of input bias in technical change

financial contagion through capital connections a model of the origin and spread of bank panics financial contagion is modeled as an equilibrium phenomenon in a dynamic setting with incomplete information and multiple banks the equilibrium probability of bank failure is uniquely determined we explore how the cross holding of deposits motivated by imperfectly correlated regional liquidity shocks can lead to contagious eects conditional on the failure of a financial institution we show that contagion is possible in the unique equilibrium of the economy and characterize exactly when it may exist at the same time we identify a direction of flow for contagious eects which provides a rationale for localized financial panics simulations identify the optimal level of interbank deposit holdings in the presence of contagion risk our results suggest that when the probability of bank failure is low maximal levels of interbank holdings are optimal when cross holding of deposits is complete we demonstrate that the intensity of contagion is increasing in the size of regionally aggregate liquidity shocks

productivity growth technical progress and efficiency in their comment subhash c ray and evangelia desli 1997 hereafter rd point out that the specification of the decomposition of the malmquist productivity index used by fare et al 1994 hereafter fgnz is not unique and propose and compute an alternative specification of that decomposition we will discuss additional decompositions at the end of this note but proceed here by comparing the rd decomposition with fgnz based on both conceptual and computational grounds rd provide a discussion of the overall malmquist productivity index including the important issue of when this index is equivalent to the traditional notion of total factor productivity tfp namely under the condition that the reference technology be consistent with constant returns to scale crs as they point out this will yield a measure of tfp even if the true underlying technology is not crs for example both rd and fgnz use the crs reference technology to compute overall malmquist productivity one of the key issues raised is the role of the underlying scale properties of the benchmark technologies used to define and compute both productivity and its components in particular two reference technologies are employed in both rd and fgnz what we refer to as crs and variable returns to scale vrs technologies by construction these technologies are nested the crs technology contains the vrs technology as in figure 1 in rd this nestedness provides the logical basis for our decomposition at a very intuitive level we would argue that these two benchmarks can be used to provide bounds on the underlying true but unknown technology 2 intuitively we see the vrs technology providing a type of convex inner approximation whereas the crs technology provides a type of convex outer approximation thus these two technologies provide alternative benchmarks they do not require that the data satisfy either crs or vrs another possible intuitive interpretation is that the crs captures a perhaps hypothetical long run and the vrs approximates the short run as a reference technology the crs technology has some very useful features for example it captures the notion of maximal

networks and economic policy over the past two decades economists have made significant advances in understanding how networks affect individual behaviour and shape aggregate outcomes we argue that insights from network economics can play an important role in the design of economic policy focusing on six policy domains we show that network economics not only deepens our understanding of existing policy concerns but also suggests a number of new policy questions in each of these policy areas we evaluate the availability of data and assess the suitability of the network economics toolkit for policy work we conclude with a discussion of challenges to the adoption of network based methods in economic policy along with strategies to overcome them

can mobile phones improve agricultural outcomes evidence from a randomized experiment in niger the widespread growth of mobile phone coverage worldwide has offered new potential for increasing rural households access to information and public and private transfers yet despite the proliferation of mobile phone based interventions in the agricultural sector there is mixed evidence on their impact we report the results of a randomized evaluation in niger in which rural households increased their access to information technology and their capacity to use it we find that households in treated villages planted a more diverse basket of crops particularly marginal cash crops grown by women this did not increase the likelihood of selling these crops or the farm gate price received suggesting that other market failures need to be addressed to improve farmers welfare

the role of networks in antitrust investigations antitrust investigations typically focus on the competitive pressures coming from within the defined markets of interest however competitive pressures can also come from other markets even when individually these markets place only weak constraints on one another collectively they may matter a networks approach to modelling competition permits a systemic view of competition that can sometimes paint a more accurate picture we demonstrate this through some simple examples and show more generally how tools from the networks literature can be applied to capture competition across a system of interrelated markets as a leading example we consider antitrust investigations into supermarkets where local geographic markets have been used as the basis of investigation

production networks and economic policy in this paper we show how to combine data on input output tables and recent insights from the theory of production networks in order to inform policy we first describe the information contained in input output tables compiled by statistical agencies and show how to derive relevant statistics of production networks we then discuss the implications of production networks for policy intervention in a series of domains such as fiscal policy industrial policy or finance finally we present a quantitative exercise applied to french data in order to illustrate that production networks shape the overall impact of competition policy on the economy

the formation of risk sharing networks this paper examines the formation of risk sharing networks in the rural philippines we find that geographic proximity possibly correlated with kinship is a major determinant of mutual insurance links among villagers age and wealth differences also play an important role in contrast income correlation and differences in occupation are not determinants of network links reported network links have a strong effect on subsequent gifts and loans gifts between network partners are found to respond to shocks and to differences in health status from this we conclude that intra village mutual insurance links are largely determined by social and geographical proximity and are only weakly the result of purposeful diversification of income risk the paper also makes a methodological contribution to the estimation of dyadic models

foreign direct investment spillovers and technical efficiency in the indonesian pharmaceutical sector firm level evidence the spillovers of foreign direct investment fdi on domestic firms performances have been highly debated for many years this article contributes to this debate by analysing spillovers effects on technical efficiency of indonesian pharmaceutical sector using a unique unbalanced panel of highly disaggregated at five digit international standard industrial classification isic 210 firms over the period 1990 1995 1001 observations the stochastic production frontier spf and the data envelopment analysis dea based on malmquist productivity indices mpi have been used to test the spillovers effects of fdi on technical efficiency the empirical results from the spf show that foreign firms are more efficient than domestic competitors and the presence of the former increases the inefficiency of the latter similarly the results from the mpi demonstrate that fdi has a negative and significant impact on technical efficiency changes in domestic competitors but generate positive spillovers to domestic s

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

the law of one price intranational evidence for canada this study investigates the behaviour of intranational prices for 45 specific consumer goods across 25 canadian cities it finds positive roles for distance and provincial borders in intercity price disparities while sizable the provincial border effect is an order of magnitude smaller than the estimates for the canada u s border a majority of the intercity relative price series are stationary around small mean values indicating that long run price differences are close to zero the intercity prices converge at rates considerably faster than the consensus estimates for international prices in fact half lives for intercity price deviations average well under a year jel classification f15 f31 la loi d un seul prix resultats intra nationaux pour le canada ce memoire examine le comportement des prix intra nationaux de 45 biens de consommation specifiques dans 25 villes canadiennes il semble que la distance et les frontieres inter provinciales ont un impact sur les differentiels de prix entre villes meme si l impact des frontieres inter provinciales est important il est beaucoupplus petit que l impact de la frontiere canada u s une majorite des series de prix relatifs entre villes sont stationnaires autour de petites valeurs moyennes ce qui suggere que les differences de prix a long terme s approchent de zero il est clair que les prix entre villes convergent a des taux considerablement plus rapides que ce qu on observe au niveau international en fait les deviations de prix entre villes ont une esperance de vie qui en moyenne est de moins d un an

multi period efficiency and malmquist productivity index in two stage production systems abstract conventional two stage data envelopment analysis dea models measure the overall performance of a production system composed of two stages processes in a specified period of time where variations in different periods are ignored this paper takes the operations of individual periods into account to develop a multi period two stage dea model which is able to measure the overall and period efficiencies at the same time with the former expressed as a weighted average of the latter since the efficiency of a two stage system in a period is the product of the two process efficiencies the overall efficiency of a decision making unit dmu in the specified period of time can be decomposed into the process efficiency of each period based on this decomposition the sources of inefficiency in a dmu can be identified the efficiencies measured from the model can also be used to calculate a common weight global malmquist productivity index mpi between two periods in that the overall mpi is the product of the two process mpis the non life insurance industry in taiwan is used to verify the proposed model and to explain why some companies performed unsatisfactorily in the specified period of time

farmer bargaining power and market information services in many sub saharan african countries farmers typically have a choice between selling their products to traders who travel between villages and markets and transporting their products to the nearest market themselves because of communities remoteness and poor communications with marketplaces farmers uncertainty about market prices is usually high traders may take advantage of farmers ignorance of the market price and extract a rent from them by offering very low prices for their products in this article we model bargaining interactions between farmers and traders meeting at the farmgate and we study how price information affects the bargain and the balance of power we show the conditions for market information services mis to be profitable for farmers and examine efficiency issues associated with asymmetric information finally we test the model s prediction that information results in positive individual gain for farmers using original survey data collected in the northern region of ghana specifically we estimate the causal effect of a mobile based mis program on farmers marketing performances and find that farmers who have benefited from the mis program received significantly higher prices for maize and groundnuts about 10 more for maize and 7 more for groundnuts than what they would have received had they not participated in the mis program these results suggest that the theoretical conditions for successful farmer use of mis may be met in the field

sectoral change catching up and slowing down oecd post war economic growth revisited abstract regression analysis of gdp growth since 1950 on pooled oecd cross sections indicates uniform technological catch up in all sectors but lower marginal labour productivity in agriculture the decline in opportunities to reallocate labour explains some of the post 1973 productivity slowdown

general equilibrium treatment effects a study of tuition policy this paper defines and estimates general equilibrium treatment effects the conventional approach in the literature on treatment effects ignores interactions among individuals induced by the policy interventions being studied focusing on the impact of tuition policy and using estimates from our dynamic overlapping generations general equilibrium model of capital and human capital formation we find that general equilibrium impacts of tuition on college enrollment are an order of magnitude smaller than those reported in the literature on microeconomic treatment effects the assumptions used to justify the late parameter in a partial equilibrium setting do not hold in a general equilibrium setting policy changes induce two way flows we extend the late concept to a general equilibrium setting we present a more comprehensive evaluation to program evaluation by considering both the tax and benefit consequences of the program being evaluated and placing the analysis in a market setting this abstract was borrowed from another version of this item

mobile phone coverage and producer markets evidence from west africa mobile phone coverage has expanded considerably throughout the developing world particularly within sub saharan africa existing evidence suggests that increased access to information technology has improved agricultural market efficiency for consumer markets and certain commodities but there is less evidence of its impact on producer markets building on the work of aker 2010 this paper estimates the impact of mobile phone coverage on producer price dispersion for three commodities in niger the results suggest that mobile phone coverage reduces spatial producer price dispersion by 6 percent for cowpea a semi perishable commodity these effects are strongest for remote markets and during certain periods of the year the introduction of mobile phone coverage has no effect on producer price dispersion for millet and sorghum two staple grains that are less perishable and are commonly stored by farmers there are no impacts of mobile phone coverage on traders gross margins or producer price levels but mobile phone coverage is associated with a reduction in the intra annual price variation for cowpea these results are potentially explained by the fact that farmers engage in greater storage for storable commodities such as millet and sorghum

trains trade and transaction costs how does domestic trade by rail affect market prices of malawi agricultural commodities this paper measures the impact of low cost transport by rail in malawi on the dispersion of agricultural commodities prices across markets by exploiting the quasi experimental design of the nearly total collapse of domestic transport by rail in january 2003 due to the destruction of a railway bridge at rivirivi balaka estimations are based on monthly market prices of four agricultural commodities maize groundnuts rice and beans in 27 local markets for the period 1998 2006 market pairs connected by rail when the railway line was operational are intervention observations railway transport services explain a 14 percent to 17 percent reduction in price dispersion across markets geographical reach of trade varies by crop most likely related to storability and geographical spread of production perishability appears to increase impact reflecting limited scope for arbitrage overall impacts are remarkably similar in size across commodities

the impact of environmental expenditures on performance in the u s chemical industry abstract this study analyzes chemical industry companies with environmental expenditures to determine which ones have better financial performance in addition this study uses data envelopment analysis to evaluate the efficiency of firms with and without environmental expenditures this study also utilizes the malmquist productivity index mpi to analyze firms productivity change and a bootstrap method to test whether the indexes are statistically significant finally this study divides chemical industry companies into three main categories based on their products the results of this study provide significant evidence of a relationship between environmental expenditures and financial performance the findings suggest that firms with environmental expenditures have better efficiency and productivity hence the study encourages companies in the industry to put more effort into protecting the environment that can be through practicing cleaner production to create higher benefits

internal borders ethnic based market segmentation in malawi summary ethnic diversity is associated with poorer economic development but why i argue that market segmentation is one mechanism linking diversity to economic underdevelopment when ethnic groups are geographically segregated and trust is concentrated within groups markets will be tend to be segmented along ethnic lines i evaluate this argument using maize price data from seventy malawian markets over 14 years and combine it with census data on the spatial distribution of ethnic groups i find that maize price differences a key indicator of market segmentation are indeed larger for ethnically dissimilar markets even after taking sub national administrative borders geographic barriers and climatic differences into account these statistical findings are complemented by interview data from farmers and traders in three markets across malawi which highlight the centrality of trust in small scale maize trading as well as a preference for coethnic trading partners together these findings suggest that ethnic diversity and ethnoregional segregation in particular can have a negative impact on market integration an important driver of food security and long term economic development

the role of environmental factors in growth accounting this paper explores a relatively new methodology the directional distance function method to analyse productivity growth the method allows us to explicitly evaluate the role that undesirable outputs of the economy such as carbon dioxide and other greenhouse gases have on the frontier production process which we specify as a piecewise linear and convex boundary function we decompose productivity growth into efficiency change catching up and technology change innovation we test the statistical significance of the estimates using recently developed bootstrap methods we also explore implications for growth of total factor productivity in the oecd and asian economies copyright 2004 john wiley sons ltd

estimating most productive scale size using data envelopment analysis abstract the relation between the most productive scale size mpss for paparticular input and output mixes and returns to scale for multiple inputs multiple outputs situations is explicitly developed this relation is then employed to extend the applications of data envelopment analysis dea introduced by charnes cooper and rhodes ccr to the estimation of most productive scale sizes for convex production possibility sets it is then shown that in addition to productive inefficiencies at the actual scale size the ccr efficiency measure also reflects any inefficiencies due to divergence from the most productive scale size two illustrations of the practical applications of these results to the estimation of most productive scale sizes and returns to scale for hospitals and stem electric generation plants are also provided emphasize the advantage of this method in examining specific segments of the efficient production surface

trade credit and the propagation of corporate failure an empirical analysis using an exhaustive data set on claims held by trade creditors suppliers on failed trade debtors customers we quantify the importance of trade credit chains for the propagation of corporate bankruptcy we show that trade creditors experience significant trade credit losses due to trade debtor failures and that creditors bankruptcy risks increase in the size of incurred losses by exploring the roles of financial constraints and creditor debtor dependences we infer that the trade credit failure propagation mechanism is driven by both credit losses and demand shrinkage finally we show that the documented propagation mechanism constitutes a significant part of the overall bankruptcy frequency suggesting that it has measurable implications for the aggregate level

structural transformation of cereal markets in ethiopia abstractwe study cereal markets in ethiopia over the last decade a period that has been characterised by important local changes including strong economic growth urbanisation improved road and communication infrastructure and higher adoption of modern inputs in agriculture these changes are associated with better spatial price integration as well as with significant declines in real price differences between supplying and receiving markets and in cereal milling and retail margins in short important improvements have occurred in ethiopia s cereal marketing system this is especially important because dysfunctional cereal markets were previously identified as an important cause of food insecurity in the country

oligopolistic pricing with sequential consumer search n identical stores compete by choosing prices for a homogeneous good with constant marginal costs consumers search sequentially with perfect recall for the lowest price one class of consumers called shoppers have zero search costs while all other consumers have a positive search cost c there is a unique symmetric nash equilibrium price distribution with the property that it changes smoothly from marginal cost pricing when all consumers are shoppers and or c 0 and monopoly pricing when no consumers are shoppers remarkably as the number of stores increases the nash equilibrium becomes more monopolistic copyright 1989 by american economic association

information efficiency and welfare in agricultural markets information and communications technologies icts have spread rapidly in the developing world there has been considerable interest in the potential role icts particularly mobile phones have begun to play in the marketing of agricultural outputs in these countries in this article we discuss the potential impacts icts may have on welfare both in terms of potential efficiency gains via improved arbitrage and welfare transfers among agents in the supply chain via reduced informational asymmetries and market power we also review the recent empirical evidence for such effects

regulatory reforms and productivity an empirical analysis of the japanese electricity industry the japanese electricity industry has experienced regulatory reforms since the mid 1990s this article measures productivity in japan s steam power generation sector and examines the effect of reforms on the productivity of this industry over the period 1978 2003 we estimate the luenberger productivity indicator which is a generalization of the commonly used malmquist productivity index using a data envelopment analysis approach factors associated with productivity change are investigated through dynamic generalized method of moments gmm estimation of panel data our empirical analysis shows that the regulatory reforms have contributed to productivity growth in the steam power generation sector in japan

credit contagion from counterparty risk standard credit risk models cannot explain the observed clustering of default some times described as credit contagion this paper provides the first empirical analysis of credit contagion via direct counterparty effects we find that bankruptcy announce ments cause negative abnormal equity returns and increases in cds spreads for credi tors in addition creditors with large exposures are more likely to suffer from financial distress later this suggests that counterparty risk is a potential additional channel of credit contagion indeed the fear of counterparty defaults among financial institu tions explains the sudden worsening of the credit crisis after the lehman bankruptcy in september 2008

sensitivity to exogeneity assumptions in program evaluation in many empirical studies of the effect of social programs researchers assume that conditional on a set of observed covariates assignment to the treatment is exogenous or unconfounded aka selection on observables often this assumption is not realistic and researchers are concerned about the robustness of their results to departures from it one approach e g charles manski 1990 is to entirely drop the exogeneity assumption and investigate what can be learned about treatment effects without it with unbounded outcomes and in the absence of alternative identifying assumptions there are no restrictions on the set of possible values for average treatment effects this does not mean however that all evaluations are equally sensitive to departures from the exogeneity assumption in this paper i explore an alternative approach developed by paul rosenbaum and donald rubin 1983 where the assumption of exogeneity is explicitly relaxed by allowing for a limited amount of correlation between treatment and unobserved components of the outcomes the starting point of the sensitivity analysis is the assumption that the exogeneity assumption is satisfied only conditional on an additional unobserved covariate making assumptions about the effect of the unobserved covariate on the outcome and its correlation with the treatment i trace out the set of possible values for the treatment effect of interest by considering a sufficiently large set of possible correlations with outcomes and treatment one can recover the bounds on the treatment effect derived by manski 1990 the approach here in the spirit of rosenbaum and rubin 1983 and rosenbaum 1995 is to allow only a limited amount of correlation and to judge the sensitivity of average treatment effect estimates to such correlations there are two novel features of the proposed analysis first rather than formulate the sensitivity in terms of coefficients on the unobserved covariate the sensitivity results are presented in terms of partial r values which may be easier to interpret second the partial r values of the unobserved covariates are compared to those for the observed covariates in order to facilitate judgments regarding the plausibility of values necessary to substantially change results obtained under exogeneity the proposed sensitivity analysis is conceptually related to the practice of assessing sensitivity of estimates by comparisons with results obtained by discarding one or more observed covariates james heckman and v joseph hotz 1989 rajeev dehejia and sadek wahba 1999 jeffrey smith and petra todd 2001 the attraction of the sensitivity analysis is that it is more directly relevant one is not interested in what would have happened in the absence of covariates actually observed but in biases that are the result from not observing all relevant covariates

telecommunications infrastructure and economic development a simultaneous approach in diesem beitrag wird untersucht welchen einflus die telekommunikations infrastruktur auf die wirtschaftliche entwicklung ausubt diese wichtige frage hat im zusammenhang mit der diskussion um informationsautobahnen aktualitat erlangt in der vorliegenden studie wird der einflus der telekommunikations infrastruktur fur 21 oecdlander fur die vergangenen 20 jahre analysiert es wird ein strukturgleichungsmodell geschatzt in dem investitionen in die telekommunikations infrastruktur als endogene variable erfast werden und in einem mikromodell angebot und nachfrage nach telekommunikations investitionen spezifiziert werden das mikromodell wird dann zusammen mit der makro wachstumsgleichung geschatzt als ergebnis stellen die autoren dann eine positive kausalbeziehung zwischen telekommunikations investitionen und wirtschaftlicher entwicklung fest wenn eine kritische masse an telekommunikations infrastruktur existiert

impact of sms based agricultural information on indian farmers this study estimates the benefits that indian farmers derive from market and weather information delivered to their mobile phones by a commercial service called reuters market light rml we conduct a controlled randomized experiment in 100 villages of maharashtra treated farmers associate rml information with a number of decisions they have made and we find some evidence that treatment affected spatial arbitrage and crop grading but the magnitude of these effects is small we find no statistically significant average effect of treatment on the price received by farmers crop value added crop losses resulting from rainstorms or the likelihood of changing crop varieties and cultivation practices although disappointing these results are in line with the market take up rate of the rml service in the study districts which shows small numbers of clients in aggregate and a relative stagnation in take up over the study period jel codes o13 q11 q13 the purpose of this study is to ascertain whether agricultural information distributed through mobile phones generates economic benefits to farmers we implement a randomized controlled trial of a commercial service entitled reuters market light rml offered by the largest and best established private provider of agricultural price information in india at the time of the experiment operating in maharashtra and other indian states rml distributes price weather and crop advisory information through sms messages we offered a one year free subscription to rml to a random sample of farmers to test whether they obtain higher prices for their agricultural output

strategic pricing consumer search and the number of firms discover prices there are three distinct price dispersed equilibria characterized by low moderate and high search intensity the effects of an increase in the number of firms on search behaviour expected prices price dispersion and welfare are sensitive i to the equilibrium consumers search intensity and ii to the status quo number of firms for instance when consumers search with low intensity an increase in the number of firms reduces search does not affect expected price leads to greater price dispersion and reduces welfare in contrast when consumers search with high intensity increased competition results in more search and lower prices when the number of competitors in the market is low to begin with but in less search and higher prices when the number of competitors is large duopoly yields identical expected price and price dispersion but higher welfare than an infinite number of firms a question that has received much attention in economic theory is how the number of competitors and market outcomes are related despite the existence of work showing the contrary see e g satterthwaite 1979 rosenthal 1980 the prediction that emerges from a market where firms interact in a cournot fashion has come to dominate economic thought namely that an increase in the number of competitors leads to larger aggregate production lower market price and improved market performance measured in terms of some social welfare criterion ruffin 1971 this paper challenges the generality of this belief by presenting an oligopoly model with consumer search where the equilibrium expected price may be constant increasing or nonmonotonic in the number of firms we present an economy with two types of consumers consumers who search for prices at no cost fully informed and consumers who must pay a fixed search cost for each price quotation they observe less informed 1 all buyers have the same willingness to pay for the good and buy either a single unit or nothing at all on the supply side of the market there are n firms producing a homogeneous good at constant marginal cost we analyse a one shot simultaneous move game firms set prices and consumers decide how many prices to search for at the same moment in time our model is essentially an oligopolistic version of burdett and judd 1983 where some consumers search costlessly in this model consumers search using a fixed sample size search strategy i e they choose the number of prices to observe before receiving any offer nonsequential search is appealing when consumers find it more advantageous to gather price information quickly morgan and manning 1985 this occurs when the search outcome is observed with delay and delay is costly for instance an mba graduate looking for a job 1 the presence in the model of consumers who search costlessly captures the fact that some people have a

networks and systemic risk in the financial system the complex web of exposures and interlinkages across the financial system highlights the relevance of network analysis in understanding systemic risk and guiding the design of financial regulation this paper discusses how network models and those based on epidemiological approaches in particular offer a compelling description of the structure of real world financial systems and shed light on different contagion mechanisms seen during the global financial crisis we also review how these insights may inform macroprudential risk assessment and policy in the areas of stress testing the financial system and the regulation of systemically important institutions the role of non bank financial intermediation and social networks in shaping financial system risk is also briefly considered

targeted carbon tax reforms abstract in the presence of intersectoral linkages sector specific carbon tax changes can have complex general equilibrium effects in particular a carbon tax on the emissions of a sector can lead to an increase in aggregate emissions we analytically characterise how incremental taxes on the emissions of any set of sectors affect aggregate emissions we show that carbon tax reforms that target sectors based on their position in the production network can achieve a greater reduction in aggregate emissions than reforms that target sectors based on their direct emissions alone we illustrate the effects of carbon tax reforms by calibrating our intersectoral network model to the economies of two countries

the effects of rural electrification on employment new evidence from south africa this paper estimates the impact of electrification on employment growth by analyzing south africa s mass roll out of electricity to rural households using several new data sources and two different identification strategies an instrumental variables strategy and a fixed effects approach i find that electrification significantly raises female employment within five years this new infrastructure appears to increase hours of work for men and women while reducing female wages and increasing male earnings several pieces of evidence suggest that household electrification raises employment by releasing women from home production and enabling microenterprises migration behavior may also be affected jel h54 l94

technical efficiency and productivity analysis in indonesian provincial economies this article estimates inefficiency and total factor productivity tfp across indonesian provinces from 1993 to 2000 indonesia is a large emerging market economy but provinces within the country due to the island structure of the country are more distinct from one another compared to other countries we use a stochastic frontier methodology to estimate inefficiency and tfp we find that tfp fell by an average rate of 7 5 across provinces due to the decrease in technical efficiency in fact the majority of output growth within indonesia is explained by the accumulation of inputs in this sense economic growth within indonesia does not appear to be sustainable without reversing these trends

malmquist productivity indexes and fisher ideal indexes comment fare and grosskopf i992 henceforth abbreviated as fg showed that under some conditions the productivity index defined as the geometric mean of two input based malmquist productivity indexes is equal to the quotient of the fisher input quantity index and the fisher output quantity index both fisher indices can be computed from observed prices and quantities these conditions appear to be so strong that they will almost certainly never be fulfilled in practice this is shown by a careful inspection of fg s proof however under slightly milder but more plausible conditions it can be shown that the quotient of the fisher input index and the fisher output index is a reasonable approximation of the productivity index consider a firm at two time periods t o i with different technologies which are modelled by the input correspondences lt y x x can produce y x c rn yce rm it is assumed that the sets lt y are closed and convex and that inputs are strongly disposable the vectors x yt wt pt t o i denote observed inputs observed outputs observed input prices and observed output prices respectively the productivity index is defined as

the law of one price in 1901 i introduction the law of one price states that absent search information costs a particular good is sold at the same price by all sellers in the same market as first pointed out by stigler 1961 however search costs can cause an equilibrium characterized by price dispersion it is no longer optimum for consumers to search until the lowest price is found as stigler observes price dispersion is a manifestation and indeed it is the measure of ignorance in the market p 214 various studies over the past four decades report evidence that price dispersion is ubiquitous and that its magnitude is affected by the costs and benefits of search for example relative dispersion the coefficient of variation is less for more expensive and frequently purchased goods where the benefits of search are greater some recent works have examined the issue in the context of internet markets e g automobiles books and cds testing the presumption that lower online search costs lead to lower price dispersion and also price levels perhaps surprisingly these studies find that dispersion in internet markets differs little from their conventional counterparts 1 the present study extends the record on price dispersion in local markets back more than a half century before the earliest modern studies circa 1960 2 this is possible because of a unique u s government survey conducted and published in 1901 the survey yields retail prices of four products at more than 1500 stores nationwide three of these are still sold today allowing comparisons based on modern survey data the intervening century saw the introduction of search cost reducing technology at least as dramatic as the internet in both transportation e g the automobile and communication e g telephone radio and television 3 also the general migration of people from the farm to cities during the early twentieth century produced a broadening of markets although not as dramatic as that created by the internet was price dispersion in 1901 more than that observed today the answer is that if anything dispersion was less in 1901 the article is organized as follows section i describes the data used in the present study section ii reports price dispersion for the four 1901 products section iii presents the modern data and makes comparisons section iv provides a summary and conclusions ii the 1901 survey in 1901 the u s industrial commission usic conducted an investigation of the local differences in prices of articles produced by certain industrial combinations usic 1901 773 the motivating concern was what is today called predatory pricing which was alleged to occur in local or regional geographic markets 4 the investigation consisted of a national survey to gather information on the prices of certain products the usic sent questionnaires to 5 000 retail dealers from whom 1 578 replies were received representing every state in the union at that time 773 74 six products were included illuminating oil kerosene granulated sugar three grades of salt and royal baking powder a specific brand the usic stated that these were chosen primarily because of the fairly uniform quality of the product which it was believed would make it possible to compare accurately the prices in different localities 773 individual dealer responses anonymous for four of these products excluding two salt grades were published in tabular form by state and city and constitute the data source for the present study 5 the issue at hand is price dispersion in a given local market the usic identifies dealers by their city of residence only and so that is the basis for market definition 6 to measure dispersion deviations from the mean there must be at least two dealers per city the first column of table 1 summarizes the number of cities markets with multiple dealers by product

expected product market reforms and technology adoption by senegalese onion producers author s bernard t de janvry a mbaye s sadoulet e abstract the authors 2017 we assess the responsiveness of senegalese onion producers to their knowledge of expected changes in product market conditions whereby onions would no longer be sold based on volume but rather on weight and with labeling certifying quality a village level randomized information campaign on the upcoming introduction of these reforms induced significant investments by farmers into quality enhancing inputs delays in the actual introduction of scales enabled us to rigorously identify positive price effects from these investments our results point to the importance of farmers expectations regarding the improved functioning of product markets in triggering technology adoption

sources of productivity growth using the fare primont decomposition an empirical application to the irish beef sector several competing methodologies for tfp estimation have been developed in the past decades a popular approach in the literature is index number computation the most widely implemented tfp indices

productivity growth technical progress and efficiency change in industrialized countries this paper analyzes productivity growth in 17 oecd countries over the period 1979 1988 a nonparametric programming method activity analysis is used to compute malmquist productivity indexes these are decomposed into two component measures namely technical change and efficiency change we find that u s productivity growth is slightly higher than average all of which is due to technical change japan s productivity growth is the highest in the sample with almost half due to efficiency change jel c43 d24 in this paper we apply recently developed

nonparametric bounds on treatment effects assume that each member of a population is characterized by values for the variables ya yb z x here x is a vector describing a person and z is a binary variable indicating which of two treatments this person receives the treatments are labelled a and b the variables ya and yb are scalar measures of the outcomes of the two treatments for example a cancer patient might be treated by a drug therapy or b surgery the relevant outcome y might be life span following treatment an unemployed worker might be given a vocational training or b job search assistance here the relevant outcome might be labor force status following treatment assume that a random sample is drawn and that one observes the realizations of z x and of the outcome under the treatment received thus ya is observed if treatment a is received but is a latent variable if treatment b is received similarly yb is either observed or latent suppose that one wants to learn the difference in expected outcome if all persons with attributes x were assigned to treatment a or b this treatment effect is

a non parametric analysis of productivity the case of u s and japanese manufacturing a nonparametric analysis of technology technical change and productivity is presented in the context of cost minimizing behavior a number of nonparametric tests concerning the existence and nature of technical change are applied to u s and japanese manufacturing data nonparametric measures of technical change are presented copyright 1990 by american economic association

from micro to macro via production networks amodern economy is an intricately linked web of specialized production units each relying on the flow of inputs from their suppliers to produce their own output which in turn is routed towards other downstream units in this essay i argue that the structure of this production network is key in determining whether and how microeconomic shocks affecting only a particular firm or technology along the chain propagate throughout the economy and shape aggregate outcomes therefore understanding the structure of this production network can better inform both academics on the origins of aggregate fluctuations and policy makers on how to prepare for and recover from adverse shocks that disrupt these production chains two recent events have brought to the forefront the importance of interconnections between firms and sectors in aggregate economic performance consider first the 2011 earthquake in japan while the triple tragedy of the earthquake the ensuing tsunami and the near nuclear meltdown at fukushima surely resulted in a significant destruction of human and physical capital its effects would have been largely restricted to the affected areas were it not for the disruption of national

the evolution and main determinants of productivity in brazilian electricity distribution 1998 2005 an empirical analysis abstract this paper estimates changes in the productivity of the brazilian electricity distribution sector using data envelopment analysis dea on a panel of 18 firms from 1998 to 2005 the study decomposes the productivity change of these distribution firms in terms of technical efficiency scale efficiency and technical progress this exercise aims to help the understanding of the main determinants of the evolution of productivity focusing its relationship with the restructuring process implemented in the 1990s tfp index records a yearly positive growth rate of 1 3 in the whole period under analysis for all firms technical change was the main component behind this evolution with an average growth of 2 1 per year while technical efficiency presented a yearly negative performance of 0 8 the results prove that in general terms the incentives generated in the reform process do not seem to have led the firms to behave in a more efficient manner

efficiency and technical progress sources of convergence in the spanish regions the paper analyses the contribution of efficiency as a mechanism of labour productivity convergence taking as the unit of analysis the spanish regions in the period 1964 1993 using the stochastic frontier approach a translogarithmic production function is estimated for the different sectors of the spanish regional economy demonstrating on this basis the existence of substantial differences in efficiency between sectors as well as between regions with regard to convergence the results obtained indicate that at aggregate level the convergence observed in labour productivity is explained by the faster growth of the capital labour ratio of the initially poorer regions and the contribution of technical change and the efficiency hence by the convergence of tfp however the information by sectors shows different results thus on the one hand the importance of the convergence in production per employee is seen in all sectors except agriculture and on the other it is observed that technical change is a

interbank contagion at work evidence from a natural experiment this article tests financial contagion due to interbank linkages for identification we exploit an idiosyncratic sudden shock caused by a large bank failure in conjunction with detailed data on interbank exposures first we find robust evidence that higher interbank exposure to the failed bank leads to large deposit withdrawals second the magnitude of contagion is higher for banks with weaker fundamentals third interbank linkages among surviving banks further propagate the shock finally we find results suggesting that there are real economic effects these results suggest that interbank linkages act as an important channel of contagion and hold important policy implications jel g01 g21 g28 e58 since the onset of the financial turmoil increased uncertainty reflected particularly in counterparty risk has led banks to hoard liquidity this has resulted in a significant decline of trading in the interbank money markets jean claude trichet president of the european central bank december 2008

is knowledge power information and switching costs in agricultural markets this article investigates an important channel through which access to information about market prices could increase the prices that producers receive from middlemen i develop a model of trade between a farmer and a middleman allowing for middlemen to differ in terms of their social preferences and provide an empirical test of the theory using a framed field experiment carried out in india the model predicts a non monotonic relationship between the benefit of information and the cost of switching to a new middleman i find that actual middlemen do differ with regard to their social preferences and that the benefit of information to the farmer varies with the cost of switching while it is not possible to confirm a non monotonic relationship between the benefit of information and the cost of switching based on these data the results are consistent with the predictions of the model

real business cycles in this paper we demonstrate how certain very ordinary economic principles lead maximizing individuals to choose consumption production plans that display many of the characteristics commonly associated with business cycles our explanation is entirely consistent with i rational expectations ii complete current information iii stable preferences iv no technological change v no long lived commodities vi no frictions or adjustment costs vii no government viii no money and ix no serial dependence in the stochastic elements of the environment we also provide a completely worked out example of the type of artificial economy we have in mind the time series properties of the example exhibit some major features of observed business cycles although this type of model may not be capable of explaining all of the regularities in actual business cycles we believe that it provides a useful well defined benchmark for assessing the relative importance of factors e g monetary disturbances

increasing returns and market efficiency in agricultural trade abstract using detailed trader surveys in benin madagascar and malawi this paper investigates the presence of increasing returns in agricultural trade after analyzing margins costs and value added we find little evidence of returns to scale motorized transport is found more cost effective for large loads on longer distances but transporters appear to pool quantities from multiple traders margin rates show little relationship with transaction size personal travel costs are a source of increasing returns but the effect is small consequently total marketing costs are nearly proportional to transaction size working and network capital are key determinants of value added constant returns to scale in all accumulable factors working capital labor and network capital cannot be rejected this implies that policies to restrict entry into agricultural trade are neither necessary nor useful governments should focus instead on technological and institutional innovations to upgrade agricultural markets

cascading failures in production networks i show how the extensive margin of firm entry and exit can greatly amplify idiosyncratic shocks in an economy with a production network i show that canonical input output models which lack the extensive margin of firm entry and exit have some crucial limitations in these models the systemic importance of a firm does not respond to productivity shocks depends only on the firm s role as a supplier and is equal to or well approximated by the firm s size this means that for every canonical input output model there exists a non interconnected model that has the same aggregate response to productivity shocks i show that when we allow for entry and exit the systemic importance of a firm responds endogenously to productivity shocks depends on a firm s role not just as a supplier but also as a consumer and a firm s systemic influence is no longer well approximated by its size furthermore i show that nondivisibilities in systemically important industries can cause one failure to snowball into a large scale avalanche of failures in this sense shocks can be amplified as they travel through the network whereas in canonical input output models they cannot