common agency with rational expectations theory and application to a monetary union we extend the theory of common agency to the situation where the principals payoffs are affected by their ex ante expectations of the agent s ex post choice we show how the usual truthful schedules must be modified to account for the rational expectations constraint we apply the model to a monetary union where member governments influence the policy of the common central bank using incentive contracts we examine how the outcomes depend on different delegated objectives of the bank and find that some often advocated rules create an excessive deflationary bias

the role of local nonfarm activities and migration in reducing poverty evidence from ethiopia kenya and uganda by using cross sectional data from ethiopia kenya and uganda this article estimates the determinants of the participation in local nonfarm activities and migration at the individual level and then estimates the determinants of farm and nonfarm income the results indicate that schooling and local language ability increase participation in local nonfarm activities and migration schooling also is found to increase nonfarm income at the household level but not farm income we also find that farm household members from low potential agricultural areas are more likely to participate in local nonfarm activities and migration than those from high potential agricultural areas thus the results suggest that local nonfarm activities and migration offer employment opportunities for workers from low potential agricultural areas indeed the nonfarm activities and migration is likely to provide an important pathway to reduce poverty in low potential agricultural areas in east africa

a multivariate sample selection model estimating cigarette and alcohol demands with zero observations heckman s sample selection model is generalized to the multivariate case and used to estimate demands for cigarettes beer and wine by individuals in the united states the specification allows correlations between the error terms of multiple selection and level equations and nests the popular bivariate sample selection model and two part model empirical results suggest that the proposed model performs better than the restricted specifications differentiated effects of variables on probabilities and levels of consumption also suggest rejection of the tobit system gender differences are present and demographic variables are more important than income in determining consumption of cigarettes beer and wine

optimal central banker contracts and common agency a comment we explore a setting where the central bank is offered an incentive scheme by an interest group in addition to the contract designed by the government we prove that the inflation bias can be eliminated when principals do not cooperate and have different output or inflation objectives these conclusions contrast with those of chortareas and miller public choice 121 131 155 2004 the reason is that our analysis takes into account the participation constraints of the central bank we also show that if principals cooperate the inflation bias is eliminated when their output target is different but not when they disagree over the inflation objective

monetary politics in a monetary union a note on common agency with rational expectations abstract is the politicisation of monetary policy in a currency union desirable this paper shows that in a setting where political influence by national governments is modeled as a common agency game with rational expectations the answer to this question crucially depends on whether the common central bank can commit to follow its policy

inflation contracts and inflation targets under uncertainty why we might need conservative central bankers this paper compares the relative effectiveness of inflation contracts and inflation targets in the presence of uncertainty regarding the central bank s preferences and the underlying output target the model explains why discretion may be superior to a delegation solution we also show that there might be the need to combine inflation targets and contracts with the appointment of a rogoff type conservative central banker if contracts and targets cannot be made state contingent and that less flexible inflation targets may be appropriate with uncertain central bank preferences

unemployment and rationality the explanation of persistent excess labor supply is a challenge to macroeconomic theorists in a purely competitive framework it may be argued that unemployment is transitory since wages will react if excess supply is persistent enough for the economy to be driven towards full employment nevertheless classical tatonement models do not support this view since excess demand functions are arbitrary see shafer and sonnenschein 1982 and convergence to the walrasian equilibrium cannot be guaranteed fixed price theory accounts for unemployment at the cost of total indeterminacy of equilibrium allocations many efforts have been made in order to narrow down this set roughly speaking these attempts can be classified into two groups i the conjectural approach cf benassy 1976 negishi 1974 grandmont and laroque 1976 and hahn 1977 1978 ii the game theoretical approach cf hart 1982 madden 1983 and silvestre 1988 in this paper we want to contribute to the first tine of thinking by applying the rationality notion developed for a conjectural equilibrium model in trujillo 1985 to a standard three goods fixed price model both kinds of equilibria are equivalent see john 1985 the motivation behind our approach is that when agents set prices they have to respect the rules of the mechanism for instance in hahn s rationality approach agents may change prices even if they are not constrained however the assumed mechanism is such that this behavior is not allowed see below therefore agents must be cheating le hahn s notion is one of incentive compatibility and it is not surprising that he obtained negative results in our approach agents may change prices if they are conjecturable in the following sense if buyers are rationed they can increase conjecture higher prices and if sellers are constrained

on the generic inefficiency of differentiable market games it is shown that a differentiable market game remains generically inefficient when its strategic outcome function is perturbed smoothly the proof is based on thom s transversality theorem and removes any restriction regarding the dimension of the strategy spaces a converse result is that almost all efficient market games that are competitive are characterized by bertrand like non differentiabilities finally a synthesis between the cournot and bertrand type approaches to walrasian equilibrium as recently developed in the literature is suggested

the role of nonfarm income in coping with the effects of drought in southern mozambique to reduce their dependence on subsistence agriculture farm households in rural africa may diversify their income sources by participating in the nonfarm sector in years of drought nonfarm income can also be part of the coping strategies a multivariate sample selection model was used to analyze three years of data from a nationally representative household survey in mozambique the analysis was guided by the following three questions during a drought year 1 do households increase their participation in nonfarm activities 2 are poorer households as likely as others to participate in and benefit from nonfarm activities and 3 which factors are associated with higher nonfarm incomes the results suggest that households are more likely to engage in at least one nonfarm income generating activity during a drought year although poorer households are more likely to engage in nonfarm activities they are less likely to participate in nonfarm activities of high return the results suggest that policies reducing entry barriers e g improved road infrastructure micro credit schemes and livestock promotion programs and increasing education levels can facilitate income diversification thus allowing rural households to better cope with the effects of drought when designing polices care must be taken to avoid exacerbating income inequality by targeting measures toward poorer and female headed households

the objective demand curve in general equilibrium with price makers objective demand curves in general equilibrium with explicitly modeled price makers have been defined so far in a number of specific cases this paper gives a general definition of such an objective demand curve the associated general equilibrium concept is defined and sufficient existence conditions are given copyright 1987 by royal economic society

agroclimatic shock income inequality and poverty evidence from burkina faso abstract this paper examines the impacts of agroclimatic shock on income inequality and poverty using household farm data from three agroecological zones of burkina faso together with income source decompositions of the gini coefficient and the foster greer thorbecke poverty index before and after a severe drought our findings reveal that because the poor lack acces to off farm income off farm income increases inequality and fails to shield poor households against agroclimatic risks the direction of the empirical relationship between changes in inequality and poverty after the drought depends critically on environmental variables and on apparent constraints on income diversification at different points in the income distribution

the dynamics of livelihood diversification in post famine ethiopia abstract based on data for almost 300 households this paper explores associations among income diversification household perceptions of livelihood risks and changes in consumption outcomes across two points in time in post famine ethiopia four key questions are addressed i to what extent did households emerging from the famine period with relatively higher income and calorie consumption levels also have a more diversified income base ii was higher income diversification in 1989 associated with higher income and consumption levels by 1994 iii which households increased their share of income from non cropping activities most during the inter survey years and iv did household heads perceive a lack of non farm income activities to be an important risk factor in famine vulnerability we find that wealthier households tended to have more diversified income streams those initially more diversified subsequently experienced a relatively greater increase in both income and calorie intake households with a greater concentration of assets were more likely to fall in their relative outcome ranking as were female headed households and initially less diversified households subsequently realized greater gains in income diversification we also find suggestive evidence that personal perceptions of risk factors guided subsequent diversification decisions

imperfect competition in auction designs we study the competition between two owners of identical goods who wish to sell them to a pool of potential buyers the sellers compete simultaneously setting reserve prices for their second price sealed bid auctions upon observing the set reserve prices the buyers decide simultaneously in which auction to bid we show that this game has at least one equilibrium and that all equilibria are inefficient reserve prices are not driven to zero cost we also discuss where and why the parallel between optimal auction design and optimal pricing in the case of monopoly breaks down for oligopoly

optimal inflation contracts and inflation targets with uncertain central bank preferences accountability through independence this paper examines some problems which arise when monetary policy is delegated to an independent central bank and where the central bank s preferences are unknown two key conclusions emerge from the paper first even with optimal targets or contracts central bank independence may not always be desirable because central banks may have distorted preferences relative to society second if the delegation solution is preferable and the independent central bank responds to information about supply shocks the central bank may be made more accountable by allowing it to set its own inflation targets i e by making it goal independent

competitivity in auction markets an experimental and theoretical investigation the authors report successive rounds of theory and laboratory experiments investigating price taking behavior and market efficiency they focus on the impact of structural parameters as well as trading institution the structural parameters involve noncompetitive supply and demand and a new odd lot trading procedure for divisible goods the trading institutions include the continuous double auction and the one shot clearinghouse as well as a new quantities only clearinghouse institution the authors present and justify an as if complete information theory that explains the competitive outcomes and that correctly predicts highly noncompetitive outcomes in quantities only clearinghouse markets copyright 1995 by royal economic society

inflation targets and contracts with uncertain central banker preferences within a standard model of monetary delegation the authors show that the optimal linear inflation contract performs strictly better than the optimal inflation target when there is uncertainty about the central banker s preferences the optimal combination of a contract and a target performs best and eliminates the inflation bias and any variability not associated with supply shocks however variability due to shocks is enhanced by uncertain central banker preferences quadratic contracts are shown to overcome this problem partly but the advantages of delegation may still be dominated by the excess variability due to shocks hence the credibility stabilization tradeoff is restored

feasible and continuous implementation there has been a great deal of research in recent years investigating the question of whether or not there exist institutions game forms for which the set of equilibria will coincide with the set of walrasian equilibria in this paper we show the existence of a game form that is feasible both for equilibrium and disequilibrium strategies continuous and for which the set of nash equilibria coincides with the set of constrained walrasian equilibria for all pure exchange economies the game form allows agents to behave strategically both with respect to their preferences and their initial endowments

have increases in federal reserve transparency improved private sector interest rate forecasts yes this paper shows that since the late 1980s u s financial markets and private sector forecasters have become 1 better able to forecast the federal funds rate at horizons out to several months 2 less surprised by federal reserve announcements 3 more certain of their interest rate forecasts ex ante as measured by interest rate options and 4 less diverse in the cross sectional variety of their interest rate forecasts we also present evidence that strongly suggests increases in federal reserve transparency played a role for example private sector forecasts of gdp and inflation have not experienced similar improvements over the same period indicating that the improvement in interest rate forecasts has been special

is the mpc s voting record informative about future uk monetary policy it is shown that the voting record of the monetary policy committee of the bank of england helps predict future policy rate changes this result is robust to the inclusion of market participants expectations as measured by the slope of the term structure of money market rates and interest rate futures moreover expectations seem to adjust to the information contained in the voting record which suggests that publishing the minutes of mpc meetings increases the transparency of monetary policy

perfectly flexible pricing in a homogeneous market so as to present our reappraisal of the implications of perfect price flexibility in the simplest possible framework we turn to marshall s 1920 book v corn market example where stocks offered for sale already exist at the outset and where equilibrium is established solely through price adjustment in this context marshall simply took it for granted that the competitive price is the unique equilibrium price op cit p 278 indeed it is clear that if prices are set by the sellers and no seller can change a quoted price then a uniform price above the competitive

central bank communication and monetary policy a survey of theory and evidence over the last two decades communication has become an increasingly important aspect of monetary policy these real world developments have spawned a huge new scholarly literature on central bank communication mostly empirical and almost all of it written in this decade we survey this ever growing literature the evidence suggests that communication can be an important and powerful part of the central bank s toolkit since it has the ability to move financial markets to enhance the predictability of monetary policy decisions and potentially to help achieve central banks macroeconomic objectives however the large variation in communication strategies across central banks suggests that a consensus has yet to emerge on what constitutes an optimal communication strategy

central banking as a political principal agent problem i introduction conventional wisdom holds that during election periods political leaders have incentives to misuse policy instruments to enhance their chances of reelection rogoff and sibert 1988 construct a rational political economy model of monetary policy based on this theme 1 the results of their model can be interpreted in the following way 2 society elects a leader every other period whose competence affects the level of output in the economy and private agents will tend to vote for the incumbent if the level of output is expected to be higher than that which can be provided by an unknown challenger voters have imperfect information regarding the politician s true impact on output and exogenous shocks to output and consequently cannot disentangle the effects of one from the other in an election period this asymmetry of information gives the incumbent an incentive to expand output through the use of inflationary monetary policy in order to appear more competent than he really is however rational voters are aware of this incentive to inflate and adjust their expectations such that in equilibrium no gain in output occurs and the economy suffers from excessive inflation an implication of the rogoff sibert model is that unless a society does away with elections as a way to choose policymakers excessive inflation and a political inflation cycle will be an unavoidable cost of democracy however societies can try and have tried to avoid these ill effects by taking the power of money creation away from the elected officials and giving it to an appointed independent central banker who will presumably pursue the public good but can this approach actually work the problem with this proposal is that the central bankers well being in many respects reappointment post central bank employment opportunities avoidance of public criticism etc often hinges on pleasing their political benefactors giving the central bankers incentives to act in the interest of elected officials 3 as a result the central banker could pursue objectives different from society s and may actually function as a veil for the elected policymaker in the real world this veil is not complete but partial and hence we can characterize the relationship between the monetary authority and society as a principal agent problem the advantage of delegating power to an appointed central banker and then erecting appropriate institutions is that the inflation problems may be resolved without abandoning the electoral process in this paper we develop a rational political business cycle model that starts from the foundations laid down by rogoff and sibert we depart from their model by having monetary policy delegated to a central banker who is appointed by the elected leaden the concern about reappointment is what motivates the agency problem the central banker would like to be reappointed and this desire leads her to partially accommodate the wishes of the current administration which in turn may not coincide with the desires of the electorate we then analyze the problem faced by a central banker who is concerned about her own selfinterest as well as social well being it is this feature that turns the setting of monetary policy into a political principal agent problem the contributions of our approach to modelling the agency problem of central banking are 1 it explicitly incorporates reappointment concerns into the decision process of the central banker which heretofore has not been done in the literature and 2 we explicitly model the source of the agency problem unlike previous research that simply assumes an agency problem exists our key results are as follows in equilibrium the pursuit of her own self interest leads the central banker to create a socially inefficient inflation bias while rogoff and sibert also obtain this result our explicit functionalform model allows us to analyze this bias in more detail and tie it directly to the strength of the relationship between the central banker and the current administration

strategy proof risk sharing abstract we consider risk sharing problems with a single good and a finite number of states agents have a common prior and their preferences are represented in the expected utility form and are risk averse we study efficient and individually rational risk sharing rules satisfying strategy proofness the requirement that no one can ever benefit by misrepresenting his preference when aggregate certainty holds we show that fixed price selections from walrasian correspondence are the only rules satisfying efficiency individual rationality and strategy proofness however when aggregate uncertainty holds we show that there exists no rule satisfying the three requirements moreover in the two agents case we show that dictatorial rules are the only efficient and strategy proof rules dropping the common prior assumption in the model we show that this assumption is necessary and sufficient for the existence of rules satisfying the three main requirements in the two agents and aggregate certainty case

linear inequality methods to enforce partnerships under uncertainty an overview we review different generic conditions on stochastic outcome functions to enforce either efficient or nearly efficient partnerships their logical relationship is explored two kinds of conditions are considered however the property for an action profile to be compatible plays a crucial role in both kinds also two kinds of enforcement mechanisms are considered enforcement through utility transfers and enforcement through repetition

optimal central banker contracts and common agency this paper considers the contracting approach to centralbanking in a simple common agency model we suggest thatcentral banker contracts that do not consider the possibilityof more than one principal existing are incomplete contracts such incomplete contracts can be a poor form ofmonetary policy delegation under common agency we develop amodel with two principals society government and ageneric interest group whose objective conflicts withsociety s ex ante preferences by incorporating an inflationarybias we determine when the government offered orinterest group offered contract dominates the central banker sdecision the results largely depend on whether theinterest group offered contract is written in terms of outputor inflation

why money talks and wealth whispers monetary uncertainty and mystique we demonstrate that in important cases propositions 3 and 4 in eijffinger hoeberichts and schaling journal of money credit and banking may 2000 may fail moreover their monetary policy delegation arrangement which advocates that central banker preference uncertainty may be desirable is dominated by other arrangements without any such uncertainty finally their way of modelling preference uncertainty leads to arbitrary effects on average monetary policy without these preference uncertainty is never desirable

is the walsh contract really optimal the purpose of this paper is to show thatthe linear penalization to inflation foundin walsh 1995 is not the government soptimal choice when the fixed part of thetransfer scheme is any given constant and thepayment to the central bank represents acost for the government

multiplicative uncertainty in a model without inflationary bias abstract this paper shows that an increase in the degree of multiplicative uncertainty regarding the effectiveness of monetary policy will reduce social loss when policymaker s preferences are highly uncertain this result is still valid even when there is no distortion in the market

can gm technologies help the poor the impact of bt cotton in makhathini flats kwazulu natal abstract the results of a two year survey of smallholders in makhathini flats kwazulu natal show that farmers who adopted bt cotton in 1999 2000 benefited according to all the measures used higher yields and lower chemical costs outweighed higher seed costs giving higher gross margins these measures showed negative benefits in 1998 99 which conflicts with continued adoption but stochastic efficiency frontier estimation which takes account of the labor saved showed that adopters averaged 88 efficiency as compared with 66 for the nonadopters in 1999 2000 when late rains lowered yields the gap widened to 74 for adopters and 48 for nonadopters

optimal degrees of transparency in monetary policymaking den meisten akademikern und politischen entscheidungstragern zufolge ist transparenz in der geldpolitik wunschenswert ich untersuche diese behauptung anhand eines kleinen theoretischen models das das vorausschauende verhalten des privaten sektors hervorhebt transparenz erleichtert es denjenigen die preise festsetzen auf die kunftigen geldpolitischen absichten der zentralbank zu schliesen wodurch die laufende inflation starker auf stabilitatspolitische masnahmen reagiert dies fuhrt dazu dass die zentralbank sich eher auf die inflation als auf die stabilisierung der produktionslucke konzentriert in diesem fall kann transparenz negative folgen haben sie kann sich sogar als eine die geldpolitik verzerrende zwangsjacke herausstellen wenn die zentralbank sich stabilitatspolitischer glaubwurdigkeit erfreut und eine aktive monetare stabilisierungspolitik benotigt wird

revisiting the role of multiplicative uncertainty in a model without inflationary bias kobayashi 2003 aims to show that in a model without inflationary bias an increase in the degree of multiplicative uncertainty on the transmission mechanism of monetary policy improves social welfare when central bank s preferences are highly uncertain we demonstrate that this result applies only to the case in which society is strictly conservative i e when the weight attached to output in the social welfare function is lower than one

general equilibrium concepts under imperfect competition a cournotian approach in a pure exchange economy we propose a general equilibrium concept under imperfect competition the cournotian monopolistic competition equilibrium and compare it to the cournot walras and the monopolistic competition concepts the advantage of the proposed concept is to require less computational ability from the agents the comparison is made first through a simple example then through a mon abstract concept the p equilibrium based on a general notion of price coordination c 1997 academic press

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

central banker contracts incomplete information and monetary policy surprises in search of a selfish central banker approaching monetary policy as a principal agent problemprovides a useful framework for interpreting alternativedelegation schemes in this paper we consider theeffectiveness of central banker incentive schemes when theprincipal delegates monetary policy through contracts butremains uncertain about the central banker s responsiveness tosuch schemes we adopt a simple principal agent model andassume that the central banker s trade off between socialwelfare and the incentive scheme is private information weconsider two types of central bankers one who responds to theincentive scheme selfish and one who does not and onlycares about social welfare benevolent we demonstratethat when a benevolent central banker accepts a contractdesigned for a selfish central banker positive inflationsurprises occur and output exceeds its natural rate wefurther show that a benevolent central banker with aninflation bias has an incentive to masquerade as selfish mechanisms exist that solve that problem by achievingpreference revelation we consider a simple mechanism indominant strategies that induces the benevolent type eithernot to breach or not to accept the appointment contract inthe first place this multi period mechanism works with eitherinflation targets or the appointment of a conservativecentral banker our results suggest that more complicatedincentive schemes embedded within broader constitutionalarrangements are required in the presence of privateinformation for them to work effectively

the walsh contract for central bankers proves optimal after all a recent paper argues that the walsh linear inflation contract does not prove optimal when the government concerns itself about the cost of the central bank contract candel sanchez campoy minarro 2004 this result relies on assuming that the participation constraint does not represent an effective constraint on the central banker s decision we show that the walsh linear inflation contract does produce the optimal outcome even when the government cares about the cost of the contract assuming that the participation constraint holds

optimal linear contracts under common agency and uncertain central bank preferences we analyze the effects of imperfectly known central banker s preferences on optimal linear contracts offered by the government and an interest group these effects depend on the type of uncertainty faced by the principals when the central bank s output target is uncertain the results by campoy and negrete public choice 137 197 206 2008 under perfectly known preferences obtain uncertainty about the central banker s degree of conservatism or about its degree of selfishness has a multiplicative impact on the principals instruments in the agent s best response function this may generate an inflation bias independently of the type of contract offered by the interest group