the stationarity of consumption income ratios evidence from bootstrapping confidence intervals abstract we study the stationarity of consumption income ratio apc in oecd countries to that end we use three different bootstrapping techniques to construct the 90 confidence intervals the results show that the apc is non stationary in most of the countries

a confirmatory analysis of the unit root hypothesis for oecd consumption income ratios this article investigates the existence of a unit root in the consumption income ratio for a sample of 23 oecd countries over the period 1960 to 2005 for that purpose we first use recently developed unit root tests with good size and power second we employ the more powerful panel unit root tests of pesaran 2003 and smith et al 2004 that take the null of nonstationarity and a bootstrap version of the test of hadri 2000 that takes stationarity as the null hypothesis overall our confirmatory analysis renders clear cut evidence that oecd consumption income ratios contain a unit root

real exchange rates under the recent float unequivocal evidence of mean reversion standard multivariate tests of long run ppp may reject nonstationarity when a single real exchange rate series is stationary we apply a test where the null hypothesis is violated only when all series are stationary and reject nonstationarity for real dollar rates

does monetary unification lead to excessive debt accumulation abstract if discretionary monetary policy gives rise to an inflation bias monetary unification boosts the accumulation of public debt the additional debt accumulation harms welfare if governments are sufficiently myopic in the presence of myopic governments debt ceilings play a useful role in avoiding excessive debt accumulation in a monetary union and allowing a conservative independent central bank to focus on price stability with supply shocks monetary unification results in excessive variability of public debt a debt target that constrains stabilization policy helps to prevent this

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

rogoff s conservative central banker restored we show that delegation of monetary policy to a weight conservative central banker can be desirable although the government can also use an inflation contract an employment target an inflation target or any combination of these to control the central banker the key feature of our model is a stochastic inflation bias arising when wage setters receive some information about a supply shock prior to signing nominal wage contracts weight conservatism is found to be desirable if fully state contingent delegation is not possible and the stochastic inflation bias cannot be eliminated by optimal choice of the delegation parameters

aggregate demand shocks central bank preferences and macroeconomic outcomes with imperfect information abstract assuming imperfect information regarding aggregate demand shocks the paper shows first the distribution of the impact of such shocks between employment and prices depends crucially on central bank preferences second optimal stabilization is achieved by a conservative central banker

political bias and war we examine the incentives for countries to go to war as they depend on the comparison between how much their pivotal decision makers have at risk and how much they stand to gain from a war how this ratio compares to the country at large is what we term political bias if there is no political bias then there are always payments that one country would like to make to the other that will avoid a war in the presence of commitment or enforceability of peace treaties if there is a bias on the part of one or both countries then war can result and in some cases cannot be prevented by any transfer payments we examine how war technology and relative wealth levels interact with political bias in determining whether countries make transfers go to war and form alliances our results shed some new light on the uneven contender paradox and the interpretation of the democratic peace

arms races and negotiations two players simultaneously decide whether or not to acquire new weapons in an arms race game each player s type determines his propensity to arm types are private information and are independently drawn from a continuous distribution with probability close to one the best outcome for each player is for neither to acquire new weapons although each prefers to acquire new weapons if he thinks the opponent will there is a small probability that a player is a dominant strategy type who always prefers to acquire new weapons we find conditions under which the unique bayesian nash equilibrium involves an arms race with probability one however if the probability that a player is a dominant strategy type is sufficiently small then there is an equilibrium of the cheap talk extension of the game where the probability of an arms race is close to zero copyright 2004 wiley blackwell

supply shocks private sector information and monetary policy is there inevitably a stabilization trade off we assume that while the central bank has an information advantage in respect of aggregate productivity shocks the private sector has superior knowledge of local disturbances it is shown that there is no policy trade off between inflation and employment stability moreover macroeconomic outcomes are independent of the weight assigned to inflation by the central bank

conflict and deterrence under strategic risk we examine the determinants of cooperation and the effectiveness of deterrence when fear is a motive for conflict we contrast results obtained in a complete information setting with those obtained in a setting with strategic risk where players have different information about their environment these two strategic settings allow us to identify and distinguish the role of predatory and preemptive incentives as determinants of cooperation and conflict in our model weapons unambiguously facilitate peace under complete information in contrast under strategic risk we show that increases in weapon stocks can have a nonmonotonic effect on the sustainability of cooperation we also show that under strategic risk asymmetry in military strength can facilitate peace and that anticipated peacekeeping interventions may improve incentives for peaceful behavior

central bank inflation contracts and strategic wage setting in a multiunion economy abstract a shared feature of models used to investigate the welfare enhancing potential of a central bank inflation contract is their stochastic nature central to the benefits conferred by such a contract is the presence of supply shocks in constructing a framework where wages are set strategically by a number of nonatomistic inflation averse unions this note identifies circumstances in which an inflation contract improves macroeconomic outcomes even in the absence of supply shocks

inflation targeting under asymmetric preferences this paper develops and estimates a game theoretical model of inflation targeting where the central banker s preferences are asymmetric around the targeted rate specifically positive deviations from the target can be weighted more or less severely than negative ones in the central banker s loss function it is shown that some of the previous results derived under the assumption of symmetry are not robust to this generalization of preferences estimates of the central banker s preference parameters for canada sweden and the uk are statistically different from the one implied by the commonly used quadratic loss function

announcements inflation targeting and central bank incentives this paper studies the incentives a central bank faces in announcing inflation targets when the central bank has private information about the economy and the public is uncertain about the central bank s preferences targeting rules in the absence of announcements reduce the inflationary bias of discretionary policy but they distort the central bank s response to private information about the economy this distortion is eliminated when the central bank is allowed to announce the inflation target announcements also affect credibility although the way they do so depends on the exact definition of credibility that is employed in standard models of monetary policy in which dynamic inconsistency plays a prominent role announcements from the central bank about its policy inten tions are not believable the central bank has an incentive to lie yet central banks often do make announcements and they are legally required to do so in some cases the bank of england for example must issue periodic inflation reports the chairman of the federal reserve is required by the humphrey hawkins act to testify before congress twice each year to explain the fed s policy actions and to detail the fed s outlook for future economic develop ments similarly the reserve bank of new zealand is required under the reserve bank act of 1989 to publish policy statements that spell out its plans the january 1994 legislation governing the banque de france requires its gov ernor to appear before parliament and the european central bank must under the maastricht treaty report at least annually to the european parlia ment if public statements about policy intentions are not credible the question naturally arises as to why central banks are frequently required to make them the answer of course is that announcements do provide the public with some information given the growing interest in policy transparency particu larly among those central banks that have adopted some form of inflation targeting it is perhaps surprising that there has been relatively little explicit analysis of how inflation targeting requirements might combine with reporting requirements to influence the informational content of announcements the conduct of stabilization policies and the central bank s credibility the purpose of this paper is to analyse the way inflation targeting affects the incentives the central bank faces in announcing targets when the central bank has private information about the economy and the public is uncertain about the central bank s preferences inflation targeting has seen increased popularity in recent years but a fixed target for inflation is generally suboptimal in the face of supply shocks while state contingent targets are viewed as not feasible an important result of this paper is that allowing the central bank to announce its own inflation target

is the consumption income ratio stationary evidence from panel unit root tests this paper provides evidence on the stationarity of the consumption income ratio from a panel of 20 oecd countries using recently developed panel unit root tests which avoid the problem of low power associated with conventional unit root tests our findings suggest that the consumption income ratios in the oecd countries are generated by a nonstationary stochastic process

a systems approach to the relationship between consumption and wealth the single equation approach to the determination of consumption due to hendry and von ungern sternberg hus is extended to a multi equation system which links decisions on consumption and the components of wealth the original hus approach has proved to be a very durable one being applicable to a number of countries and macroeconomic models this approach is extended to allow a role for rates of return as well as income and it is shown how this extension results in an error correction system the empirical analysis used is based on johansen s maximum likelihood extension of the co integration approach of engle and granger

crucial issues concerning central bank independence abstract this paper argues first that it is inappropriate to presume that central banks will in the absence of any tangible precommitment technology inevitably behave in a discretionary fashion that implies an inflationary bias furthermore there is no necessary tradeoff between flexibility and commitment second to the extent that the absence of any precommitment technology is nevertheless a problem it will apply to a consolidated central bank plus government entity as well as to the central bank alone thus contracts between governments and central banks do not overcome the motivation for dynamic inconsistency they merely relocate it several implications are discussed

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

stochastic trends and economic fluctuations are business cycles mainly the result of permanent shocks to productivity this paper uses a long run restriction implied by a large class of real business cycle models identifying permanent productivity shocks as shocks to the common stochastic trend in output consumption and investment to provide new evidence on this question econometric tests indicate that this common stochastic trend cointegration implication is consistent with postwar u s data however in systems with nominal variables the estimates of this common stochastic trend indicate that permanent productivity shocks typically explain less than half of the business cycle variability in output consumption and investment copyright 1991 by american economic association

a cointegration analysis of the impact of the age structure of the population on the household saving rate in japan this paper analyzes the impact of the age structure of the population on japan s household saving rate by applying cointegration techniques to time series data for the 1955 1993 period it finds th

causality in crude oil prices crude oil markets witness growing disparity between the quality of crudes supplied and demanded in the market the market share of low quality crudes is increasing due to the depletion of old fields and increasing demand this is unnerving the practitioners and affecting the relevance of the traditional benchmark crudes due to the lack of lower quality benchmarks montepeque 2005 in this article we apply granger causality tests to study the price dependence of 32 crudes in order to establish which crudes drive other prices and which ones simply follow general market trends our results indicate that some of the old benchmarks are still relevant while others can be disregarded our results also interestingly show that the low quality mediterranean russian urals crude introduced in the late 1990s has emerged recently as a significant driver of global prices

monetary policy delegation and polarisation there is by now a comprehensive literature beginning with rogoff 1985 arguing that a government should delegate monetary policy to a central banker who is independent and more conservative than the government itself this will reduce the inflationary bias typically at the cost of stabilisation for a democratic society this result would suggest that the median voter should prefer that monetary policy is delegated to an independent central banker who is more conservative than herself typically the central banker is chosen by the government and the government is chosen by the electorate thus there is some albeit perhaps a weak link between the preferences of the electorate and the central banker although the central banker presumably should be chosen for a long period of time waller and walsh 1996 he has to be chosen at some point in time this paper contains a political economy model where the central issue in politics is the choice of central banker and

war politics an economic rational voter framework the frequency of foreign conflict initiations in the united states is found to be significantly greater following the onset of recessions during a president s first term than in other periods the authors develop an economic theory of the political use of wars which links the election cycle war decisions and economic performance consistent with the observed relationships among these events an incumbent leader with an unfavorable economic performance record may initiate a war to force the learning of his war leadership abilities and thus salvage with some probability his reelection this obtains despite voter rationality and informational symmetry copyright 1995 by american economic association

public debt indexation and denomination with an independent central bank abstract this paper examines the interaction between public debt management and the design of monetary institutions the analysis shows that delegation of monetary policy to an independent central bank is more effective in containing inflationary expectations than the use of foreign currency or inflation indexed debt if delegation of monetary policy is viable the optimal policy is to issue nominal debt this increases the sensitivity of taxes and output to unexpected inflation thus minimizing the inflation needed to offset supply shocks evidence on central bank independence debt composition and output variability suggests that the normative argument has some positive content

incumbent performance and electoral control in the pure theory of electoral competition citizens compare the platforms of the candidates and vote for the one whose platform is preferred candidate strategies are identified with promises about future performance in office models of this sort have been developed in both static mckelvey 1975 and dynamic kramer 1977 i settings and all appear to have the property that if the set of alternatives is large enough in some sense equilibrium platforms rarely exist but these models have another feature that is quite as disturbing as their instability in the static setting discussed by mckelvey little attention is paid to the possibility that once in office the politician s preferences may diverge from those of his constituents and that he may therefore choose policies at variance from his platform instead it is simply assumed that promises will be kept whether or not such behavior is congruent with the interest of the officeholder it is sometimes argued that an enforcement mechanism may exist to discipline politicians for failing to keep promises but without a specification of the mechanism it is not obvious that it would be in the interests of the

an investigation of the long run properties of aggregate non durable consumers expenditure in the united this paper estimates the effects of the modeling of nondurable consumption in the light of the five years of new data since the publication of the paper by j e h davidson et al 1978 and the development of the new cointegration technique of r f engle and c w j granger 1987 existing models are found to be inadequate on two grounds they fail parameter stability tests and they do not contain a suitable equilibrium specification the paper uses the cointegration approach to search for an encompassing model that is both stable and cointegrates the main finding is that the analysis must be extended to allow for differential income effects caused by changing higher rate income tax bands copyright 1989 by royal economic society

the nairu unemployment and monetary policy this paper examines the precision of conventional estimates of the nairu and the role of the nairu and unemployment in forecasting inflation the authors find that although there is a clear empirical phillips relation the nairu is imprecisely estimated forecasts of inflation are insensitive to the nairu and there are other leading indicators of inflation that are at least as good as unemployment this suggests deemphasizing the nairu in public discourse about monetary policy and instead drawing on a richer variety of leading indicators of inflation

political macroeconomics a survey of recent developments the paper surveys political macroeconomics covering its development from rogoff s conservative central banker to the most recent discussions of monetary policy and institutional design topics include the inflation stabilization trade off central bank independence with escape clauses and overruling with costs inflation targets performance contracts for monetary authorities and the consequences of output persistence for these issues further topics are the political business cycle when output is persistent the political macroeconomics of fiscal policy the government spending bias and the game theoretic interaction between fiscal and monetary policy all work is discussed within a coherent analytical framework

optimal monetary policy cooperation through state independent contracts with targets abstract simple state independent monetary institutions are shown to secure optimal cooperative policies in a stochastic linear quadratic two country world with international policy spill overs and national credibility problems institutions characterize delegation to independent central bankers facing quadratic performance related contracts punishing or rewarding deviations from primary and intermediate policy targets

inflation government transfers and optimal central bank independence abstract the problem of monetary policy delegation is formulated as a two stage non cooperative game between the government and the central bank the solution to this policy game determines the optimal combination of central bank conservatism and independence the results show that the optimal institutional design always requires some degree of central bank independence and that there is substitutability between central bank independence and conservatism the results also show that partial central bank independence can be optimal and that there are circumstances under which it is optimal for the government to appoint a liberal central banker

game theory and the spiral model when one state engages in a military buildup other states sometimes take this as a sign that it is more aggressive or expansionist than they previously thought some argue that such increases in mutual suspicion can drive arms races and even lead to war psychological bias is often invoked to explain this pattern of growing suspicions leading to hostility this article presents an incomplete information model of an arms race and investigates when escalations should rationally generate increased fears and when in order to reduce such fears security seekers can refrain from building it shows that escalations rationally provoke fear even in the absence of bias and that weak states and states facing high costs of arms racing and war will be especially likely to refrain from building as a way of signaling benign intentions

rationalist explanations for war realist and other scholars commonly hold that rationally led states can and sometimes do fight when no peaceful bargains exist that both would prefer to war against this view i show that under very broad conditions there will exist negotiated settlements that genuinely rational states would mutually prefer to a risky and costly fight popular rationalist and realist explanations for war fail either to address or to explain adequately what would prevent leaders from locating a less costly bargain essentially just two mechanisms can resolve this puzzle on strictly rationalist terms the first turns on the fact that states have both private information about capabilities and resolve and the incentive to misrepresent it the second turns on the fact that in specific strategic contexts states may be unable credibly to commit to uphold a mutually preferable bargain historical examples suggest that both mechanisms are empirically plausible

the political economy of inflation labour market distortions and central bank independence using the citizen candidate model we study the government s choice of institutions for the labour market and the central bank and derive the implications for inflation and employment we derive conditions for the existence of equilibria in which the labour market is distorted and the central bank is dependent or independent under a range of conditions affecting central bank dependence the post election cycle in inflation and employment and inflation bias our results imply that average inflation and inflation variability are lower under an independent central bank whereas employment variability can be lower or higher consistent with evidence for oecd countries many democratic societies delegate key tasks to non elected and independent institutions a prominent example being independent central banks the belief in the advantage of central bank independence is nursed by the cross country evi

the optimality of a monetary union without a fiscal union the paper explores the case for monetary and fiscal unification monetary policy suffers from an inflation bias because the monetary authorities are not able to commit with international risk sharing fiscal discipline suffers from moral hazard an inflation target alleviates the inflation bias but weakens fiscal discipline in a monetary union however this adverse effect on fiscal discipline is weaker this advantage of monetary unification may outweigh the disadvantage of not being able to employ monetary policy to stabilise country specific shocks while monetary unification may thus be optimal international risk sharing may be undesirable because it weakens fiscal discipline

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

war and conflict in economics theories applications and recent trends we review the main economic models of war and conflict these models vary in details but their implications are qualitatively consistent highlighting key commonalities across a variety of conflict settings recent empirical literature employing both laboratory and field data in many cases confirms the basic implications of conflict theory however this literature also presents important challenges to the way economists traditionally model conflict we finish our review by suggesting ways to address these challenges

a bargaining model of partisan appointments to the central bank abstract in this paper a bargaining model is developed to analyze the appointment of central bankers in a two party political system the major results of the paper are 1 the party in power will appoint partisans early on but later appointments will be increasingly moderate in their views concerning monetary policy 2 changing the timing of the appointment of the board chairman from the end of a president s term in office to the first period of the president s term will lead to more partisan monetary policy 3 in equilibrium nominations to the board are not rejected thus confirmation hearings appear to be nothing more than a rubber stamp process 4 lengthening the terms on the board relative to the electoral cycle will lead to more moderate appointments to the central bank and a reduction in partisan policymaking

domestic political survival and international conflict is democracy good for peace we build a game theoretic model where aggression can be triggered by domestic political concerns as well as the fear of being attacked in the model leaders of full and limited democracies risk losing power if they do not stand up to threats from abroad in addition the leader of a fully democratic country loses the support of the median voter if he attacks a non hostile country the result is a non monotonic relationship between democracy and peace using polity data we classify countries as full democracies limited democracies and dictatorships for the period 1816 2000 correlates of war data suggest that limited democracies are more aggressive than other regime types including dictatorships and not only during periods when the political regime is changing in particular a dyad of limited democracies is more likely to be involved in a militarized dispute than any other dyad including mixed dyads where the two countries have different regime types thus while full democratization might advance the cause of peace limited democratization might advance the cause of war we also find that as the environment becomes more hostile fully democratic countries become more aggressive faster than other regime types

debt contingent inflation contracts and targets abstract this paper analyzes fiscal and monetary policy interaction in a simple policy game with debt and output shocks seigniorage provides revenue for the government but results in an inflation bias we analyze three mechanisms designed to eliminate some or all of the biases in monetary policy an inflation performance contract inflation target both contingent on the stock of debt and a zero inflation rule the performance contract and inflation target result in higher interest rate remove all biases in monetary policy and achieve the pre commitment policy hence they are equivalent the first two solutions also yield a higher expected welfare than a zero inflation policy

new panel unit root tests of ppp abstract we use the new panel unit root tests im k s pesaran m h shin y 1995 testing for unit roots in heterogenous panels wp 9526 dae university of cambridge revised march 1997 to analyse the stationarity of real exchange rates for the g10 economies and switzerland our results for monthly data 1973 96 indicate mean reversion in real exchange rates and a half life of under three years for one off shocks

the stationarity of consumption income ratios evidence from minimum lm unit root testing abstract previous research concerning the stationarity of the consumption income ratio is extended via the application of the minimum lm unit root tests of lee and strazicich 2003 lee j and strazicich m 2003 minimum lm unit root test with two structural breaks review of economics and statistics 85 1083 1089 it is found that incorporation of structural change under the null reverses earlier findings of non stationarity with the unit root hypothesis rejected for all 20 oecd economies examined

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

regime type the fate of leaders and war we propose and test a formal model of war and domestic politics building on recent evidence on the relationship between regime type the effect of war on the probability of losing office and the consequences of losing office the less the outcome of international interaction affects a leader s tenure and the less punitive are the consequences of losing office the more a leader is willing to make concessions to strike a peaceful bargain we demonstrate that our theory successfully predicts war involvement among nondemocratic regime types moreover our theory offers an intuitive explanation for the democratic peace compared to nondemocratic leaders the tenure of democratic leaders depends relatively little on the war outcome and democratic leaders fare relatively well after losing office thus democratic leaders should be more willing and able to avoid war especially with other democrats

rationalizability learning and equilibrium in games with strategic complementarities we study a rich class of noncooperative games that includes models of oligopoly competition macroeconomic coordination failures arms races bank runs technology adoption and diffusion r d competition pretrial bargaining coordination in teams and many others for all these games the sets of pure strategy nash equilibria correlated equilibria and rationalizable strategies have identical bounds also for a class of models of dynamic adaptive choice behavior that encompasses both best response dynamics and bayesian learning the players choices lie eventually within the same bounds these bounds are shown to vary monotonically with certain exogenous parameters we study the class of noncooperative supermodular games introduced by topkis 1979 and further analyzed by vives 1985 1989 who also pointed out the importance of these games in industrial economics supermodular games are games in which each player s strategy set is partially ordered the marginal returns to increasing one s strategy rise with increases in the competitors strategies so that the game exhibits strategic complementarity 2 and if a player s strategies are multidimensional marginal returns to any one com ponent of the player s strategy rise with increases in the other components this class turns out to encompass many of the most important economic applications of noncooperative game theory in macroeconomics diamond s 1982 search model and bryant s 1983 1984 rational expectations models can be represented as supermodular games in each of these models more activity by some members of the economy raises the returns to increased levels of activity by others in oligopoly theory some models of bertrand oligopoly with differentiated products qualify as supermodu lar games in these games when a firm s competitors raise their prices the marginal profitability of the firm s own price increase rises a similar structure is present in games of new technology adoption such as those of dybvig and spatt 1983 farrell and saloner 1986 and katz and shapiro 1986 when more users hook into a communication system or more manufacturers adopt an interface standard the marginal return to others of doing the same often rises similarly in some specifications of the bank runs model introduced by diamond and dybvig 1983 when more depositors withdraw their funds from a bank it is more worthwhile for other depositors to do the same in the warrant exercise

is the consumption income ratio stationary in african countries evidence from new time series tests that allow for structural breaks abstractthis article examines whether the consumption income ratio is stationary in 50 african countries we use the residual augmented least squares rals lm unit root test that allows for struct

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

accountability transparency and inflation targeting inflation targeting regimes define a performance measure for the central bank a regime that places a large small weight on achieving the target is analogous to a high low powered incentive scheme high powered incentive structures promote accountability but may distort stabilization policy the optimal power under inflation targeting is derived under perfect and imperfect information the fundamental trade off between accountability and stabilization depends on the degree of transparency defined as the ability to monitor the central bank s performance multiplicative uncertainty increases the optimal weight to place on achieving an inflation target