bubbles and experience an experiment we investigate the occurrence of bubble crash pricing patterns in laboratory financial markets with a mixture of experienced and inexperienced traders we find that even with a minority of experienced traders bubbles are substantially abated

fixing exchange rates a virtual quest for fundamentals abstract fixed exchange rates are less volatile than floating rates but the volatility of macroeconomic variables such as money and output does not change very much across exchange rate regimes this suggests that exchange rate models based only on macroeconomic fundamentals are unlikely to be very successful it also suggests that there is no clear tradeoff between reduced exchange rate volatility and macroeconomic stability

real exchange rate volatility and economic openness theory and evidence this paper relates the volatility of the trade weighted effective real exchange rate to the degree of trade openness of an economy the theoretical part presents an intertemporal monetary model of a small open economy with nominal rigidities both monetary and aggregate supply shocks are shown to produce ceteris paribus smaller real exchange rate movements if the country is more open to foreign trade empirical evidence on a cross section of forty eight countries confirms this relationship differences in trade openness explain a large part of the cross country variation in the volatility of the effective real exchange rate

bubbles and total factor productivity evidence shows that asset price bubbles typically precede financial crises and financial crises are accompanied by the collapse of bubbles in addition stock market booms and busts are typically associated with credit market booms and busts the recent us housing and stock market bubbles and the subsequent great recession that began in late 2007 provide an example the stock market booms in the early 1990s and the subsequent asian financial crisis in 1997 provide another example there are also many other related episodes of financial crises in emerging economies motivated by these observations miao and wang 2011a propose a theory of credit driven stock price bubbles we show that a positive feedback loop mechanism generates stock price bubbles when firms borrow against the stock market value of their collateralized assets to finance investment we assume that firms face stochastic investment opportunities and bubbles improve investment efficiency we also study stochastic bubbles and policy implications in the present paper we apply the theory developed by miao and wang 2011a to an environment in which firms face idiosyncratic productivity shocks and credit constraints we show that both bubbleless and bubbly equilibria bubbles and financial crisis

are price limits really bad for equity markets despite widely documented criticisms price limit rules are present in many equity markets around the world using a game theoretic model we argue that if the cost of monitoring a market is high price limit rules are beneficial empirical tests based on a cross section of 43 equity markets across five continents support our theoretical prediction we find that the probability of the existence of price limit rules is greater in markets that incur higher monitoring costs due to poorer business disclosure more corruption and less efficiency in legal regulatory and technological environments

effects of treatment beyond the treated a general equilibrium impact evaluation of lesotho s cash grants program africa s social cash transfer programs target the most resource constrained households unlikely to expand supply in response to transfer induced demand we propose a local economy wide impact evaluation model and use it to evaluate local spillovers from lesotho s child grants program we report monte carlo confidence bounds around impact simulation results we find significant spillovers to nonrecipient households and significant real income multipliers although the latter are dampened if factor supply constraints generate excessive inflationary pressures our findings raise questions about how to measure the impacts of cash transfers evaluations focusing only on eligible households are likely to significantly understate program impacts

adoption of improved maize varieties in southern ethiopia factors and strategy options abstract this paper identifies factors that influence the decision behavior of farmers in southern ethiopia in adopting improved maize varieties by estimating a logistic regression data for this study came from 222 farmers interviewed as part of a national adoption survey conducted in three selected maize growing administrative zones of southern ethiopia in 1998 the paper also assesses the impact of pure and mixed strategy options on the probability of adoption of improved maize varieties through simulation under different scenarios as far as pure strategies are concerned the credit strategy is more powerful than the others in terms of raising the probability of adoption however results from the analysis of pure versus mixed strategies imply that mixed strategies are no necessarily much better than pure strategies

thar she bursts reducing confusion reduces bubbles to explore why bubbles frequently emerge in the experimental asset market model of smith suchanek and williams 1988 we vary the fundamental value process constant or declining and the cash to asset value ratio constant or increasing we observe high mispricing in treatments with a declining fundamental value while overvaluation emerges when coupled with an increasing c a ratio a questionnaire reveals that the declining fundamental value process confuses subjects as they expect the fundamental value to stay constant running the experiment with a different context stocks of a depletable gold mine instead of stocks significantly reduces mispricing and overvaluation as it reduces confusion jel c91 d14 g11 g12

biogas energy from family sized digesters in uganda critical factors and policy implications dependence on fossil energy sources is increasingly becoming unsustainable due to ecological and environmental problems and rapid depletion biogas energy could augment these conventional energy sources but despite its advantages and favourable conditions for its production biogas energy use in uganda remains low due to technical economic and socio cultural impediments based on primary data on households in central and eastern uganda and the use of logistic regression this study analyses factors affecting the adoption of biogas energy in uganda the empirical results suggest that the probability of a household adopting biogas technology increases with decreasing age of head of household increasing household income increasing number of cattle owned increasing household size male head of household and increasing cost of traditional fuels in contrast the likelihood of adoption decreases with increasing remoteness of household location and increasing household land area policy options and recommendations including educational and awareness campaigns on biogas benefits and successes the provision of financial and non financial incentives to households and establishment of an institutional framework could bolster wider biogas energy acceptance in uganda

do regulations work a comprehensive analysis of price limits and trading restrictions in experimental asset markets with deterministic and stochastic fundamental values abstract we examine how traders react to two prominent stock market regulations under a constant fundamental value fv process price limits and trading restrictions significantly reduce the price level and mispricing size when traders are inexperienced under a markov process fv there is no evidence for these regulations to reduce mispricing the novel markov process also serves as a testbed for several financial hypotheses related to the regulations we find that price limits do not improve reactions to market news and the binding of price limits magnifies the momentum in the price movements these findings suggest that the scope of these regulations is limited and that they can backfire in some market environments

ngos agricultural technology and the rural poor abstract a wide range of agencies outside the public and private commercial sectors is involved in generating introducing testing and promoting agricultural technology particularly for small farmers and landless labourers in marginal areas of less developed countries their experience is largely undocumented and tends to be overlooked for specific locations this paper discusses the significance of different types of voluntary agency vis a vis the public sector focusing on non government organizations it then examines in what roles they can be expected to perform well although still fragmentary the evidence from africa asia and latin america indicates substantial unexploited complementarities between agencies within and outside the public sector

bubbles crashes and endogenous expectations in experimental spot asset markets1 spot asset trading is studied in an environment in which all investors receive the same dividend from a known probability distribution at the end of each of t 15 or 30 trading periods fourteen of twenty two experiments exhibit price bubbles followed by crashes relative to intrinsic dividend value when traders are experienced this reduces but does not eliminate the probability of a bubble the regression of changes in mean price on lagged excess bids number of bids minus the number of offers in the previous period p pt a f b 1 o l supports the hypothesis that a e d the one period expected value of the dividend and that f 0 where excess bids is a surrogate measure of excess demand arising from homegrown capital gains losses expectations thus when bt 1 o goes to zero we have convergence to rational expectations in the sense of fama 1970 that arbitrage becomes unprofitable the observed bubble phenomenon can also be interpreted as a form of temporary myopia tirole 1982 from which agents learn that capital gains expectations are only temporarily sustainable ultimately inducing common expectations or priors tirole 1982 four of twenty six experiments all using experienced subjects yield outcomes that appear to the chart s eye to converge early to rational expectations although even in these cases we get 0 and small price fluctuations of a few cents that invite scalping

participation public policy political economy and development in rural bangladesh 1958 85 abstract during this period four successive regimes in bangladesh have felt reluctantly compelled to set up structures for local participation in government each found it had to reach out beyond the support of urban and rural elites and the military if it was to move beyond mere stability to real development of the country despite many problems most notably local elite takeover at local level and military coup at national level there is considerable evidence particularly from neighboring india to suggest that local participatory institutions can be successful over the longer term in promoting development for the middle and the poorer rural classes

traders expectations in asset markets experimental evidence we elicit traders predictions of future price trajectories in repeated experimental markets for a 15 period lived asset we find that individuals beliefs about prices are adaptive and primarily based on past trends in the current and previous markets in which they have participated most traders do not anticipate market downturns the first time they participate in a market and when experienced they typically overestimate the time remaining before market peaks and downturns occur when prices deviate from fundamental values belief data are informative to an observer in predicting the direction of future price movements and the timing of market peaks

bubble formation and in efficient markets in learning to forecast and optimise experiments this experiment compares the price dynamics and bubble formation in an asset market with a price adjustment rule in three treatments where subjects 1 submit a price forecast only 2 choose quantity to buy sell and 3 perform both tasks we find deviation of the market price from the fundamental price in all treatments but to a larger degree in treatments 2 and 3 mispricing is therefore a robust finding in markets with positive expectation feedback some very large recurring bubbles arise where the price is three times larger than the fundamental value which were not seen in former experiments

who benefited from burundi s demobilization program this paper assesses the impact of the demobilization reinsertion and reintegration program in post war burundi two major rebel groups benefited from cash and in kind transfers the cndd fdd from 2004 and the fnl from 2010 a panel data of households collected in 2006 and 2010 is combined with official records from the national commission for demobilization reinsertion and reintegration regression analysis shows that the cash payments received by fnl demobilized households had a positive impact on consumption nonfood spending and investments the program also generated positive spillovers in the villages where fnl combatants returned ex combatants indeed spent a large part of their allowance on consumption goods and clothing thereby generating a short run economic boom in villages however the long run evolution of consumption indicators is negative for cndd fdd households as well as for villages where cndd fdd combatants returned suggesting that the direct impact and the spillovers of the program vanished in the long run

the impact of perception and other factors on the adoption of agricultural technology in the moret and jiru woreda district of ethiopia the objectives of this study are to examine both the significance of the impact of farmers perceptions regarding new technology for the adoption decision and how perceptions themselves are influenced by the decision to adopt new technology the study is based on data from 96 wheat farms in the moret and jiru woreda district of ethiopia the probit approach is used to analyse the adoption decision while the variables relevant to farmers perceptions are modelled using the ordered probit methodology a simultaneous equations model combining the probit and ordered probit approaches provides a useful approach to modelling the two way relationship between perception and adoption variables such as farm size farm income and soil type have a key role to play in the model perception is measured by eight different components and as there is a strong collinearity among these various measures a principal components analysis is attempted to draw the best possible linear combination of variables

classroom games speculation and bubbles in an asset market this paper describes a classroom exercise in which students trade assets of uncertain value in a sequence of market periods assets pay one dollar dividends at the end of each period but once the dividend is paid there is fixed probability that the asset will be destroyed dividends and probabilities are chosen so that the fundamental value is constant over time speculative bubbles can be caused by divergent expectations about other traders valuations of the asset this exercise provides an interactive framework that facilitates discussions of discounting rational expectations and backward induction

price bubbles and crashes in experimental call markets abstract price bubbles relative to intrinsic dividend value are observed using a call market trading institution market prices tend to track intrinsic value only when the same group of highly experienced traders participate in three consecutive 15 round markets

international risk cycles abstract recent work in international finance suggests that exchange rate puzzles can be accounted for if 1 aggregate uncertainty is time varying and 2 countries have heterogeneous exposures to a world aggregate shock we embed these features in a standard two country real business cycle framework and calibrate the model to equity risk premia in low and high interest rates countries unlike traditional real business cycle models our model generates volatile exchange rates a large currency forward premium excess comovement of asset prices relative to quantities and an imperfect correlation between relative consumption growth and exchange rates our model implies however that high interest rate countries have smoother quantities equity returns and interest rates than low interest rate countries contrary to the data

adoption of agricultural innovations in developing countries a survey this paper reviews various studies which have provided a description and possible explanation to patterns of innovation adoption in the agricultural sector the survey points out that the tendency of many studies to consider innovation adoption in dichotomous terms adoption nonadoption may not be appropriate in many cases where the actual decisions are defined over a more continuous range more attention needs to be given to the socio cultural and institutional environment in area studies so that their interrelation with economic factors affecting adoption can be inferred the presence of several interrelated innovations is another aspect that needs to be considered more carefully in future research since a number of simultaneous decisions may be involved furthermore the possibility of regular sequential patterns in adopting components of a new technological package should be specifically addressed in future studies finally the impact of differential adoption rates on land holding distribution merits attention in future research

a unique t 1 trading rule in china theory and evidence abstract unique to the world china adopts a t 1 trading rule which prevents investors from selling stocks bought on the same day we develop a dynamic price manipulation model to study the effects of the t 1 trading rule compared to the t 0 trading rule which allows investors to buy and sell the same stocks during the same day we show that the t 1 trading rule reduces the total trading volume and price volatility and improves the trend chasers welfare when trend chasing is strong an empirical test using data on china s b share stock market supports the model s theoretical predictions

unpacking the meaning of market access evidence from rural kenya summary this paper critically examines the dimensions of market access using farm panel survey data from kenya we investigate changes in ten indicators of market access during the 1997 2010 post liberalization period we find major improvements in certain market access conditions and little change in others there is generally low correlation between alternative indicators of market access all purpose indicators may not accurately reflect specific market access conditions of interest distances to physical infrastructure are often not representative of farmers access to markets changes in specific market access conditions may have more to do with the behaviors of marketing agents we consider the implications of these findings for agricultural marketing policies and for research methods

the overvaluation of purchasing power parity abstract recent panel studies of purchasing power parity have reported strong evidence of mean reversion in real exchange rates however these studies fail to control for cross sectional dependence in the data this failure has dramatic consequences raising the significance level of tests with a nominal size of 5 percent to as much as 50 percent it is shown in this paper that controlling for cross sectional dependence no evidence against the random walk null can be found in panels of up to 64 real exchange rates this finding cannot be attributed to low power as there is ample power in panels of this size to reject the unit root null

institutional development the world bank and india s new agricultural extension programme the new world bank sponsored and funded training and visit system of agricultural extension represents a major attempt by the bank to promote institutional development the very considerable investment has in fact resulted in little change or improvement in the quality of extension the reasons lie in failure to analyse the cause of the weakness of the previous extension systems inherent defects of the training and visit system and the way in which it has been introduced into india these failures in turn can be explained by the interests and the politics underlying the programme

the impact of monetary policy on stock market bubbles and trading behavior evidence from the lab we investigate the effect of monetary policy on stock market bubbles and trading behavior in experimental asset markets we introduce the possibility of investing in interest bearing bonds to the widely used laboratory asset market design of smith et al 1988 treatment groups face a variable interest rate policy which depends on asset prices while control groups are subjected to a constant interest rate we observe a strong impact of our interest rate policy on liquidity in the stock market but only a small impact on bubbles however we find that announcing the possibility of reserve requirements significantly reduces bubbles

investor attention overconfidence and category learning abstract motivated by psychological evidence that attention is a scarce cognitive resource we model investors attention allocation in learning and study the effects of this on asset price dynamics we show that limited investor attention leads to category learning behavior i e investors tend to process more market and sector wide information than firm specific information this endogenous structure of information when combined with investor overconfidence generates important features observed in return comovement that are otherwise difficult to explain with standard rational expectations models our model also demonstrates new cross sectional implications for return predictability

the political realities of african management abstract amidst the outburst of concern for public management in africa there is frequently a failure to distinguish among its components policy making leadership general internal administration and bureaucratic hygiene accounting procurement the merit system etc each of these four areas is different in the importance that it has for project performance the knowledge base that is available for improving it and the way in which it is affected by african political and social structures as a consequence those seeking to improve public management on the continent frequently are mistaken in the priorities that they establish and import inappropriate management technologies

thar she blows gender competition and bubbles in experimental asset markets do women and men behave differently in financial asset markets our results from an asset market experiment show a marked gender difference in producing speculative price bubbles mixed markets show intermediate values and a meta analysis of 35 markets from different studies confirms the inverse relationship between the magnitude of price bubbles and the frequency of female traders in the market women s price forecasts also are significantly lower even in the first period implications for financial markets and experimental methodology are discussed jel d14 d81 g01 g11 j16

sources of innovation in agricultural technology abstract this paper focuses attention on environmental and biological characteristics of agriculture which shape the process of technical innovation the interaction of natural selection and human purposive selection and experimentation is shown to result in a continuous process of innovation placing farmers in the informal r and d systems as well as scientists in formal r and d systems in an innovative treadmill the importance and limitations of informal r and d are reviewed a discussion of the characteristics and potential of formal r and d systems leads to the identification of some major problems of policy inherent in and specific to the organization and management of agricultural research resources these include genetic vulnerability choices between environmentally specific or widely adapted technologies the location of research activity the linkages between agricultural producers and scientists and methods for maintaining and strengthening informal r and d systems

can trade costs explain why exchange rate volatility does not feed into consumer prices abstract if countries specialize in imperfectly substitutable goods trade costs increase the share of expenditure devoted to domestic output reducing the exposure of consumer price inflation to exchange rate changes i present a multi country flexible price model where expenditure shares are inversely related to trade costs through a gravity equation in this setting consumer price inflation can be approximated as an expenditure share weighted average of the contributions to inflation from all countries i use data from 24 oecd countries 1970 2003 to estimate a structural gravity model i combine the fitted expenditure shares from the estimation with actual data on exchange rates to construct predictions of inflation the behavior of these predictions indicates that trade costs can explain both qualitatively and quantitatively the failure of exchange rate volatility to feed into inflation

to see is to believe common expectations in experimental asset markets abstract we experimentally manipulate agents information regarding the rationality of others in a setting in which previous studies have found irrationality to be present namely the asset market experiments introduced by smith et al 1988 recent studies suggest that mispricing in such markets may be an artefact of confusion which can be reduced by training subjects to understand the diminishing fundamental value we reconsider this view and propose that when it is made public knowledge that training has occurred this may also reduce uncertainty over the behavior of others and facilitate the formation of common expectations our design disentangles the direct effect of training from the indirect effect of its public knowledge and our results demonstrate a distinct and statistically significant effect of public knowledge over and above that of training alone

handbook of international economics vol 2 this handbook adopts a traditional definition of the subject and focuses primarily on the explanation of international transactions in goods services and assets and on the main domestic effects of those transactions the first volume deals with the real side of international economics it is concerned with the explanation of trade and factor flows with their main effects on goods and factor prices on the allocation of resources and income distribution and on economic welfare and also with the effects on national policies designed explicitly to influence trade and factor flows in other words it deals chiefly with microeconomic issues and methods the second volume deals with the monetary side of the subject it is concerned with the balance of payments adjustment process under fixed exchange rates with exchange rate determination under flexible exchange rates and with the domestic ramifications of these phenomena accordingly it deals mainly with economic issues although microeconomic methods are frequently utilized especially in work on expectations asset markets and exchange rate behavior

underreaction to fundamental information and asymmetry in mispricing between bullish and bearish markets an experimental study abstract in contrast to existing literature we implement experimental asset markets with fluctuating fundamental values following a stochastic process therefore we can measure traders behavior in both bullish and bearish markets we observe underreaction of price changes to changes in fundamental value which induces overvaluation in bearish and undervaluation in bullish markets we also find an asymmetry between markets with bullish fundamental values and those with bearish ones as the former markets show a higher degree of informational efficiency the reason for the observed underreaction lies in the relatively large volatility of the underlying fundamental value process

agriculture and economic growth in ethiopia growth multipliers from a four sector simulation model abstract agriculture accounts for over half of ethiopian gdp yet the case for agriculture as a focus of economic growth strategies must rely on identifying a set of intersectoral linkages through which agricultural growth contributes to the growth of non agriculture in the ethiopian economy this article develops a four sector numerical simulation model of economic growth in ethiopia which permits the calculation of macroeconomic growth multipliers resulting from income shocks to agriculture services modern industry and traditional industry the resulting growth multipliers are 1 54 for agriculture 1 80 for services 1 34 for modern industry and 1 22 for traditional industry these results depict an economy in which intersectoral linkages operate on a highly uneven basis these limits are reflected in the wide disparity between sectoral growth multipliers and by substantial differences in the patterns of their decomposition the policy relevance of these findings relate in part to the distributional implications of growth in particular sectors poverty in ethiopia is disproportionately rural an income shock to agriculture is clearly the most progressive choice indicating the need to highlight agricultural development in growth strategies for ethiopia yet the simulation results further indicate that doing so imposes relatively little trade off against total benefit while a 1 service sector income shock generates 0 80 in indirect benefits a 1 agricultural income shock still generates 0 54 in indirect gains a somewhat smaller benefit but one likely to make the greatest possible impact on poverty reduction

innovation technical assistance and development the importance of technology users abstract in both industrialized and developing country situations technology users play a key role in generating successful new products and processes both high tech innovation such as the design of the boeing 747 aircraft and ibm computer software and innovative technologies for the rural poor such as vietnamese expeller pumps and bangladeshi hybrid rice strains owe much to the creativity and skill not of research scientist but of local housewives farmers and artisans new approaches to technical assistance which increase the interaction between r d institutions and these technology users are needed in order to tap this important innovation resource the incorporation of such an interactive research strategy into the work of the sudan energy research council led to highly successful initiatives in the fields of charcoal production improved charcoal stoves and agroforestry

agricultural research effort conceptual clarity and measurement abstract this paper emphasizes the need for basic conceptual clarity regarding the measures of research effort in econometric analyses this conceptual clarity could help reduce the misinterpretation of historical and institutional contexts underlying agricultural research effort after a brief review of econometric studies estimating the returns to and determinants of research the centrality of the conceptual contextual and causal significance of this measure is examined conceptualized and measured at the input frontier of the research process an expenditure measure of research reveals the institutional features and changes in the research process in india over time this basic understanding is essential to develop appropriate econometric specifications and correspondingly effective research policy statements

a macroprudential approach to financial regulation many observers have argued that the regulatory framework in place prior to the global financial crisis was deficient because it was largely microprudential in nature a microprudential approach is one in which regulation is partial equilibrium in its conception and aimed at preventing the costly failure of individual financial institutions by contrast a macroprudential approach recognizes the importance of general equilibrium effects and seeks to safeguard the financial system as a whole in the aftermath of the crisis there seems to be agreement among both academics and policymakers that financial regulation needs to move in a macroprudential direction in this paper we offer a detailed vision for how a macroprudential regime might be designed our prescriptions follow from a specific theory of how modern financial crises unfold and why both an unregulated financial system as well as one based on capital rules that only apply to traditional banks is likely to be fragile we begin by identifying the key market failures at work why individual financial firms acting in their own interests deviate from what a social planner would have them do next we discuss a number of concrete steps to remedy these market failures we conclude the paper by comparing our proposals to recent regulatory reforms in the united states and to proposed global banking reforms

district level economic linkages in kenya evidence based on a small regional social accounting matrix abstract this paper explores the nature and extent of the economic linkages in a small regional economy defined by a market center and its hinterland in kenya the analysis is based on a set of income and employment multipliers derived from a social accounting matrix estimated for the region issues considered include the impact of production activities on regional value added and employment the influence of sectoral production on the level of household income and the impact of household expenditure on regional value added and the relative significance of production and consumption linkages in terms of stimulating aggregate income the above questions are examined under the assumption of complete excess capacity in regional production and under the assumption of supply constraints in agriculture the usefulness of the analysis for district level economic planning is demonstrated

a multiple source of innovation model of agricultural research and technology promotion abstract two models of agricultural research and technology diffusion are described and contrasted the central source of innovation model frequently underlies the theories and rhetoric of agricultural research and extension institutions the multiple source of innovation model places agricultural research and diffusion processes in the historical political economic agroclimatic and institutional context in which technological change takes place the paper discusses the evidence and reasons for the dominance of the central model and reviews the significance of the multiple source model for agricultural research policy

the economic impacts of drought on the economy of iran an integration of linear programming and macroeconometric modelling approaches in this paper we provide economy wide estimates of the costs of drought in the cropping sector of the iranian economy using a linear programming model to estimate the direct costs on agriculture and a macroeconometric model to trace the indirect impacts on the rest of the economy the results indicate that a severe drought such as the one that occurred in the crop year 1999 2000 imposes a direct cost of 1605 million usd equivalent to 30 3 of the total value added of the cropping sector in iran this in turn leads to a 12 7 reduction in the value added of other agricultural sub sectors livestock fisheries and forestry in the rest of the economy the manufacturing and service sectors experience value added declines of 7 8 and 3 7 respectively in addition there is a substantial decrease in investment in the agricultural manufacturing and service sectors thus such a drought reduces overall gdp by about 4 4 and it would also result in decreased non oil exports increased food imports and a rise in inflation the results of some drought mitigation simulations are reported in brief such estimates strengthen the case for increased attention to drought strategies and management in agriculture in iran and elsewhere

the effect of short selling on bubbles and crashes in experimental spot asset markets a series of experiments illustrate that relaxing short selling constraints lowers prices in experimental asset markets but does not induce prices to track fundamentals we argue that prices in experimental asset markets are influenced by restrictions on short selling capacity and limits on the cash available for purchases restrictions on short sales in the form of cash reserve requirements and quantity limits on short positions behave in a similar manner a simulation model based on delong et al 1990 generates average price patterns that are similar to the observed data asset market bubbles are persistent deviations of prices from fundamentals to the extent that bubbles exist they can influence investment levels and the allocation of capital and thereby have considerable economic effects in recognition of their potential importance the question of the existence and pervasiveness of bubbles has been a focus of extensive empirical investigation see e g shiller 1981 blanchard and watson 1982 diba and grossman 1988 and west 1988 these studies yield mixed results regarding the empirical relevance of bubble phenomena one source of the differences in conclusions may be that because the fundamental value of the assets cannot be observed tests of the presence of bubbles are joint tests with the particular specification of the process guiding the evolution of fundamentals also being tested the availability of short selling is widely believed to make bubble formation less likely one rationale for such a belief is the notion that the cause of asset market bubbles is a constraint on the ability of traders to speculate on future downward price movements see e g miller 1977 jarrow 1980 diamond and verrecchia 1987 or figlewski and webb 1993 in the absence of short sales traders may sell only the shares in their portfolios the availability of short sales relaxes this constraint in this paper we study empirically the effect of allowing short sales on both the incidence and magnitude of market bubbles we choose a setting in which the fundamental value of the asset is clearly and unambiguously defined and known at all times and bubbles typically occur namely we use the experimental environment that smith suchanek and williams 1988 introduce while

a reappraisal of the extent of world hunger abstract the variation between different estimates of the magnitude of the world food problem are enormous the author questions the basis of the major surveys of fao the world bank and usda and suggests that they have grossly overestimated the extent of worid hunger by analysing the connection between population food and economic participation a more realistic view is obtained suggesting a return to targeted assistance programmes for the improvement of maternal and child health

rational asset pricing bubbles this paper provides a fairly systematic study of general economic conditions under which rational asset pricing bubbles may arise in an intertemporal competitive equilibrium framework our main results are concerned with nonexistence of asset pricing bubbles in those economies these results imply that the conditions under which bubbles are possible including some well known examples of monetary equilibria are relatively fragile this paper is concerned with the conditions under which asset prices in an intertemporal competitive equilibrium are equal to the present value of the streams of future dividends to which each asset represents a claim according to a central result of the theory of finance this is very generally true in the case of economies with trading at only a finite sequence of dates as long as there are no restrictions upon transactions other than that associated with possible incom pleteness of the set of securities that are traded the result is sometimes called the fundamental theorem of asset pricing here we consider the extent to which such a result continues to be valid in the case of trading over an infinite horizon it has often been observed in the econometric literature on asset pricing bubbles that it is possible in principle for the price of a perpetuity and the dividends on that security to satisfy at all times a present value relation for one period holding returns while the security s price nonetheless does not equal the present value of the stream of dividends expected over the infinite future in such a case the price of the perpetuity is said to involve a bubble component 2 joint stochastic processes for which this component is nonzero are sometimes argued to characterize existing assets for a recent example see froot and obstfeld 1991 but such an inference depends upon aspects of the stochastic

nonspeculative bubbles in experimental asset markets lack of common knowledge of rationality vs actual irrationality we report the results of an experiment designed to study the role of speculation in the formation of bubbles and crashes in laboratory asset markets in a setting in which speculation is not possible bubbles and crashes are observed the results suggest that the departures from fundamental values are not caused by the lack of common knowledge of rationality leading to speculation but rather by behavior that itself exhibits elements of irrationality much of the trading activity that accompanies bubble formation in markets where speculation is possible is due to the fact that there is no other activity available for participants in the experiment

the federal reserve and panic prevention the roles of financial regulation and lender of last resort this paper surveys the role of the federal reserve within the financial regulatory system with particular attention to the interaction of the fed s role as both a supervisor and a lender of last resort the institutional design of the federal reserve system was aimed at preventing banking panics primarily due to the permanent presence of the discount window this new system was successful at preventing a panic in the early 1920s after which the fed began to discourage the use of the discount window and intentionally create stigma for window borrowing policies that contributed to the panics of the great depression the legislation of the new deal era centralized fed power in the board of governors and over the next 75 years the fed expanded its role as a supervisor of the largest banks nevertheless prior to the recent crisis the fed had large gaps in its authority as a supervisor and as lender of last resort with the latter role weakened further by stigma the fed was unable to prevent the recent crisis during which its lender of last resort function expanded significantly as the fed begins its second century there are still great challenges to fulfilling its original intention of panic prevention

market imperfections access to information and technology adoption in uganda challenges of overcoming multiple constraints limited empirical evidence exists on how multiple binding constraints influence the adoption of improved technologies by smallholder farmers this article uses the case of groundnut variety adoption in uganda to investigate the role of information seed supply and credit constraints in conditioning technology uptake new data from a household survey in seven groundnut growing districts n 945 indicate that 8 of farmers lack information on new varieties while 18 and 6 of farmers respectively cannot adopt mainly due to seed supply and capital constraints a tobit type specification that considers all nonadopters as being uninterested in the technology i e corner solutions would lead to inconsistent parameter estimates and incorrect conclusions in this context we therefore estimate a modified multi hurdle specification of demand for new varieties taking into account how information seed supply and capital constraints jointly determine adoption probability and intensity the study reveals new empirical insights on why agricultural technology adoption in africa has lagged behind slow uptake is not mainly due to a lack of economic incentives but rather a reflection of information seed supply and credit constraints that prevent farmers from translating their desired demand into adoption of modern varieties policy implications are discussed

price limit performance evidence from the tokyo stock exchange price limit advocates claim that price limits decrease stock price volatility counter overreaction and do not interfere with trading activity conversely price limit critics claim that price limits cause higher volatility levels on subsequent days volatility spillover hypothesis prevent prices from efficiently reaching their equilibrium level delayed price discovery hypothesis and interfere with trading due to limitations imposed by price limits trading interference hypothesis empirical research does not provide conclusive support for either positions we examine the tokyo stock exchange price limit system to test these hypotheses our evidence supports all three hypotheses suggesting that price limits may be ineffective

systems of innovation theory and the changing architecture of agricultural research in africa abstract this paper examines the on going evolution of the organisational architecture of agricultural research in africa once considered a rural backwater populated by agronomists extension agents and farmers agricultural research is now being explicitly placed within global debates about innovation technology institutions and development this is reflected in a growing interest in the use of systems of innovation theory to both understand and reform innovation processes within agriculture the basic argument put forward in the paper is that the conception of a global agricultural research system and associated efforts to create a coordinated multi layered supra national research infrastructure are at odds with both the realities of research at national level and the bio physical and socio economic heterogeneity that characterises rural africa it is suggested that a less directive approach to support for agricultural research is required to allow national characteristics and differences to come to the fore and to give more room for the development of the all important demand side

trade costs asset market frictions and risk sharing i use bilateral import data to test for and quantify the importance of trade costs and asset market frictions in explaining the failure of perfect international consumption risk sharing i find that while frictions in international asset markets significantly impede optimal consumption risk sharing between developed and developing countries over the period 1970 2000 developed countries are close to optimal risk sharing with each other trade costs in contrast sig

asset holdings caps and bubbles in experimental asset markets abstract we report the results of an experiment designed to study the effect of individual asset holdings restrictions on the formation of bubbles and crashes in laboratory asset markets bubbles and crashes are a quite robust phenomenon in experimental settings motivated by demand control policies employed in the chinese real estate market we explore the effects of permanent and short term caps on individual asset holdings we find that permanent caps greatly reduce positive bubbles but tend to generate negative bubbles in later periods under short term caps on the other hand neither positive nor negative bubbles are observed our results indicate that asset holdings caps can be effective in eliminating bubbles if properly designed

speculative markets and the effectiveness of price limits abstract the aim of this paper is to study the effectiveness of price limits in speculative markets we construct a nonlinear stochastic asset pricing model in which traders rely on technical and fundamental analysis to determine their orders the dynamics of the model mimic stylized facts such as the emergence of bubbles excess volatility fat tails for returns or volatility clustering quite well using this model as a laboratory we find that price limits have the potential to reduce both volatility and deviations from fundamentals the more traders lend themselves to trend extrapolating behavior the better price limits work

business cycles and the exchange rate system some international evidence this paper investigates the differences in time series behavior of key economic aggregates under alternative exchange rate systems we use a postwar sample of 49 countries to compare the behavior of output consumption trade flows government consumption spending and real exchange rates under alternative exchange rate systems pegged floating and cooperative systems such as the ems we then examine evidence from two particular episodes involving canada and ireland of changes in the exchange rate system aside from greater variability of real exchange rates under flexible than under pegged nominal exchange rate systems we find little evidence of systematic differences in the behavior of macroeconomic aggregates or international trade flows under alternative exchange rate systems these results are of interest because a large class of theoretical models implies that the nominal exchange rate system has important effects on a number of macroeconomic quantities

poverty status and the impact of formal credit on technology use and wellbeing among ethiopian smallholders summary this paper examines the impact of formal credit largely microfinance on the use of improved technology and on consumption and asset growth across households in different degrees of asset poverty using data from rural ethiopia the analysis finds no relationship between participation in microfinance programs and the use of technologies or consumption growth among the poorest households even though the use of certain technologies like fertilizer contributes to their asset accumulation over time for other households microfinance has positive effects on both consumption and asset growth as well as on the use of improved technology the findings imply variation in constraints faced by different classes of poor households and suggest the value of asset based poverty classifications in identifying target groups for poverty interventions

price bubbles gender and expectations in experimental asset markets abstract this paper reports results of laboratory markets for a risky asset with a flat fundamental value that equates expected dividends to the return on a safe asset subjects were sorted by gender in an unobtrusive manner and bubbles in this setting are pervasive and of comparable magnitude for both genders in contrast a robustness check done with a declining fundamental value did generate larger bubbles for groups of males elicited price forecasts tend to trail share prices as they rise and exceed prices as they fall a pattern that is tracked by a double adaptive forecasting model

private agricultural research in asia abstract agricultural research in south and south east asia was started by a mix of private companies commodity groups and governments in the 1960s and 1970s government research increased rapidly commodity groups declined in importance and there were signs of private research growth recently the increased demand for modern inputs and changes in government policy provide greater incentives for private research but first they have to resolve a number of issues about the role private research should play in their societies

farm nonfarm linkages in rural sub saharan africa this paper is an accumulation over the past 25 years of a body of detailed work examining the structure of africa s rural nonfarm economy first it systematically reviews empirical evidence on the nature and magnitude of the african rural nonfarm economy it then explores differences across locality and size across countries and over time in an effort to assess likely patterns of growth a subsequent review of key production and consumption parameters allows an estimate of the magnitude of the agricultural growth multipliers in africa the paper concludes with a brief discussion of policies and programs that will be necessary if farm nonfarm growth linkages are to achieve their full potential

thar she blows can bubbles be rekindled with experienced subjects we report 28 new experiment sessions consisting of up to three experience levels to examine the robustness of learning and error elimination among participants in a laboratory asset market and its effect on price bubbles our answer to the title question is yes we impose a large increase in liquidity and dividend uncertainty to shock the environment of experienced subjects who have converged to equilibrium and this treatment rekindles a bubble however in replications of that same challenging environment across three experience levels we discover that the environment yields a rare residual tendency to bubble even in the third experience session therefore a caveat must be placed on the effect of twice experienced subjects in asset markets in order for price bubbles to be extinguished the environment in which the participants engage in exchange must be stationary and bounded by a range of parameters experience including possible error elimination is not robust to major new environment changes in determining the characteristics of a price bubble jel c91 d83

recession depression mental health effects of the 2008 stock market crash do sudden large wealth losses affect mental health we use exogenous variation in the interview dates of the 2008 health and retirement study to assess the impact of large wealth losses on mental health among older u s adults we compare cross wave changes in wealth and mental health for respondents interviewed before and after the october 2008 stock market crash we find that the crash reduced wealth and increased feelings of depression and use of antidepressant drugs and that these effects were largest among respondents with high levels of stock holdings prior to the crash these results suggest that sudden wealth losses cause immediate declines in subjective measures of mental health however we find no evidence that wealth losses lead to increases in clinically validated measures of depressive symptoms or indicators of depression

the purchasing power parity debate originally propounded by the 16th century scholars of the university of salamanca the concept of purchasing power parity ppp was revived in the interwar period in the context of the debate concerning the appropriate level at which to re establish international exchange rate parities broadly accepted as a long run equilibrium condition in the post war period it first was advocated as a short run equilibrium by many international economists in the first few years following the breakdown of the bretton woods system in the early 1970s and then increasingly came under attack on both theoretical and empirical grounds from the late 1970s to the mid 1990s accordingly over the last three decades a large literature has built up that examines how much the data deviated from theory and the fruits of this research have provided a deeper understanding of how well ppp applies in both the short run and the long run since the mid 1990s larger datasets and nonlinear econometric methods in particular have improved estimation as deviations narrowed between real exchange rates and ppp so did the gap narrow between theory and data and some degree of confidence in long run ppp began to emerge again in this respect the idea of long run ppp now enjoys perhaps its strongest support in more than 30 years a distinct reversion in economic thought

agricultural technology and farm nonfarm growth linkages abstract agricultural growth stimulates rural nonfarm activity by boosting demand for production inputs and consumer goods but different kinds of agricultural technology promote different patterns of nonfarm linkages to explore how key features of agricultural technology affect growth in the rural nonfarm economy this paper reviews an array of cross section and time series evidence bearing on the dynamics of the rural nonfarm economy then using consumption and production parameters associated with different agricultural technologies it introduces a simple model which isolates the effects of different technologies on nonfarm growth linkages

a review of bubbles and crashes in experimental asset markets this paper discusses the literature on bubbles and crashes in the most commonly used experimental asset market design introduced by smith et al it documents the main findings based on the results from 41 published papers 3 book chapters and 20 working papers

why research partnerships really matter innovation theory institutional arrangements and implications for developing new technology for the poor abstract this paper explores the conceptual basis for existing and emergent institutional patterns in the context of partnership approaches to technology development drawing examples from recent studies of private enterprise activity in india smallholder horticulture it suggests that agricultural innovation as a process involves a wider range of organizational types than the conventional policy focus on public sector research organizations would tend to suggest it uses the concept of a national innovation system to argue that a partnership approach is adopted as a core methodology for engaging science and technology development with the livelihood demands of the poor

measuring the restrictiveness of trade policy this article provides an introduction to the trade restrictiveness index tri which equals the uniform tariff that is welfare equivalent to a given pattern of trade protection unlike standard measures of trade restrictiveness the tri has a solid theoretical basis can incorporate both tariffs and quantitative restrictions and can be adapted to construct the trade policy equivalent of domestic distortions the article compares a number of applications and describes procedures for operationalizing the tri on a personal computer the authors conclude that the tri has considerable potential in empirical work

a theory of price limits in futures markets abstract the existence of price limits in certain futures markets is explained by demonstrating that price limits may act as a partial substitute for margin requirements in ensuring contract performance their effectiveness is a decreasing function of the amount of information available to traders about the equilibrium futures price which is unobservable in the event of a limit move and the theory predicts that no limits will exist in the markets for financial futures actual limits are broadly consistent with the theory his interpretation plausible as it was was totally misleading with the dangerous verisimilitude of a theory which will fit all or nearly all the facts and yet more entirely miss the truth by a mere accident then would a frank perplexity heritage v sackville west