endogenous trading constraints with incomplete asset markets abstract this paper endogenizes the borrowing constraints on capital in a production economy with incomplete markets we find that these limits get looser with income a property that is consistent with us data on credit limits the framework with endogenous limits is then used to study the effects of a revenue neutral tax reform that eliminates capital income taxes our results illustrate that it is very important to take into account the effects of tax policies on the limits throughout the transition these effects can be big enough to change the overall conclusion about the desirability of a tax reform

wealth distribution in life cycle economies abstract this paper compares the age wealth distribution produced in life cycle economies to the corresponding distribution in the us economy the idea is to calibrate the model economies to match features of the us earnings distribution and then examine the wealth distribution implications of the model economies the findings are that the calibrated model economies with earnings and lifetime uncertainty can replicate measures of both aggregate wealth and transfer wealth in the us furthermore the model economies produce the us wealth gini and a significant fraction of the wealth inequality within age groups however the model economies produce less than half the fraction of wealth held by the top 1 percent of us households

an inventory model for deteriorating items with stock dependent consumption rate and shortages under inflation and time discounting this paper derives an inventory model for deteriorating items with stock dependent consumption rate and shortages under inflation and time discounting over a finite planning horizon we show that the total cost function is convex with the convexity a simple solution algorithm is presented to determine the optimal order quantity and the optimal interval of the total cost function the results are discussed with a numerical example and particular cases of the model are discussed in brief a sensitivity analysis of the optimal solution with respect to the parameters of the system is carried out

on the empirics of foreign aid and growth the present paper re examines the effectiveness of foreign aid theoretically and empirically using a standard olg model we show that aid inflows will in general affect long run productivity the size and direction of the impact may depend on policies deep structural characteristics and the size of the inflow the empirical analysis investigates these possibilities overall we find that aid has been effective in spurring growth but the magnitude of the effect depends on climate related circumstances finally we argue that the collier dollar allocation rule should be seriously reconsidered by donor agencies if aid effectiveness is related to climate the usefulness of foreign aid in promoting growth in developing countries has been an area of controversy ever since rosenstein rodan in 1943 advocated for aid to eastern and south eastern europe browsing through successive editions of a leading textbook in development economics provides a telling illustration of how the confidence in aid effectiveness dwindled over the years in the first edition of leading issues in economic development meier 1964 dedicated a full 18 page section to the issue of foreign aid he started out asking how much aid by the time of the sixth edition meier 1995 the treatment of foreign aid had been cut into half and the questions in focus were why official assistance and does aid work in the 2000 edition meier and rauch 2000 foreign aid is not even listed in the index

modelling long term oil price and extraction with a hubbert approach the lopex model abstract the lopex l ong term o il p rice and ex traction model generates long term scenarios about future world oil supply and corresponding price paths up to the year 2100 in order to determine oil production in non opec countries the model uses hubbert curves hubbert curves reflect the logistic nature of the discovery process and the associated constraint on temporal availability of oil extraction paths and world oil price path are both derived endogenously from opec s intertemporally optimal cartel behaviour thereby opec is faced with both the price dependent production of the non opec competitive fringe and the price dependent world oil demand world oil demand is modelled with a constant price elasticity function and refers to a scenario from acropolis poles lopex results indicate a significant higher oil price from around 2020 onwards compared to the reference scenario and a stagnating market share of maximal 50 to be optimal for opec

liquidity constrained markets versus debt constrained markets this paper compares two different models in a common environment the first model has liquidity constraints in that consumers save a single asset that they cannot sell short the second model has debt constraints in that consumers cannot borrow so much that they would want to default but is otherwise a standard complete markets model both models share the features that individuals are unable to completely insure against idiosyncratic shocks and that interest rates are lower than subjective discount rates in a stochastic environment the two models have quite different dynamic properties with the debt constrained model exhibiting simple stochastic steady states while the liquidity constrained model has greater persistence of shocks

an introduction to the wage curve en conomists and policymakers are interested in understanding the forces that determine the level of unemployment and the level of wages this paper describes an empirical discovery made with the help of international microeconometric evidence covering more than a dozen nations about a link between these two variables the connection can be portrayed on a graph with the level of unemployment on the horizontal axis and the level of wages on the vertical axis then the wage curve as shown in figure 1 is a downwardsloping locus this relationship tells us that holding others things constant if a region has a rise in unemployment in a particular year those who live there will have a fall in their wages in that year what does this curve mean how in a field where fully controlled experiments are almost impossible could there be any convincing scientific basis for this wage curve what is the relationship between the wage curve and a phillips curve other than that the curve of figure 1 looks like a phillips curve with the vertical axis mislabeled how does the wage curve fit into existing economic knowledge and is the empirical finding consistent with competitive theory this paper sketches answers to these kinds of questions the discussion draws on our book the wage curve blanchflower and oswald 1994 where the points raised here are investigated more fully it also rests upon work done by other economists whose work is listed in the paper and the bibliography

major oil exporters may profit rather than lose in a carbon constrained world the organization of petroleum exporting countries opec claims compensation for losses in expected oil export revenues due to co2 mitigation measures in developing countries these losses are expected for two primary reasons a reduction in the consumption of oil in importing countries and a reduction in the producer price of oil taxation in an importing country implies a transfer of rents from producers to consumers so far most studies have focused on these two mechanisms and corroborated that revenue losses for opec are to be expected however there are also mechanisms that may be expected to raise the price of oil products in a cost effective regime for dealing with climate change i e a regime in which all or most countries participate and in which the same carbon price is applied on all carbon emitting activities the cost of using unconventional oil or synthetic diesel from coal will increase even more than the cost of using conventional oil given that reserves of conventional oil are expected to dwindle over time heavy oils and coal to liquids might set the long run price for liquid fuels which means that the price of oil would increase beyond the carbon fee i e the rent on conventional oil would increase we use an energy economic optimization model to analyze these three mechanisms we find that the net present value of opec revenue from conventional oil increases slightly at most by 4 percent with a global co2 restriction regime we also consider conditions under which this result does not hold

endogenous debt constraints in a life cycle model with an application to social security this paper develops a simple life cycle model that embeds a theory of debt restrictions based on the existence of inalienable property rights a la kehoe and levine 1993 debt constrained asset markets review of economic studies 60 4 865 888 2001 liquidity constrained markets versus debt constrained markets econometrica 69 3 575 598 in our environment net debtors have the option of defaulting on unsecured debt at the cost of being subjected to wage garnishment and or having some or all of their future assets seized by creditors one advantage of our framework is that it encompasses two standard versions of the life cycle model one with perfect capital markets and one with a non negative net worth restriction we study the impact of a payroll financed social security system to illustrate the role of endogenous debt constraints and compare our results to a model with exogenous debt constraints whereas the aggregate effects are similar under both types of constraints the distributional consequences are found to be significantly different across debt regimes

integrating deterioration and lifetime constraints in production and supply chain planning a survey abstract items with short lifetimes that are subject to deterioration are important in the business world research has a long tradition in integrating deterioration and value loss effects into mathematical models for inventory planning and control where such effects are understood as a general loss or shrinkage of inventory however there has been little work in the modeling of lifetime restrictions of items to prevent wastage and disposals especially in a dynamic planning context globalization and other trends extend the consideration of single companies to whole supply chains implying increased coordination and information needs this is important as planning decisions impact lead times and thus the quality of items in the whole supply chain products that exceed their useful lifetime can impose high costs due to inventory loss or the need to rework them this implies increased utilization of scarce resources e g machine time metals and or energy thereby increasing co 2 levels we survey the state of the art regarding depreciation effects and the modeling of lifetime constraints as well as a classification of models following business planning functions of the value chain a critical evaluation of approaches and their limitations is provided highlighting directions for future research

models of energy use putty putty versus putty clay energy use is inelastic in time series data but elastic in international cross section data two models of energy use reproduce these elasticities a putty putty model with adjustment costs developed by pindyck and rotemberg 1983 and a putty clay model in the pindyck rotemberg model capital and energy are highly complementary in both the short run and the long run in the putty clay model capital and energy are complementary in the short run but substitutable in the long run we highlight the differences in the cross section implications of the models by considering the effect of an energy tax on output in both models in the putty putty model an energy tax that doubles the price of energy leads to a fall in output in the long run of 33 in contrast the same tax in the putty clay model leads to a fall in output of only 5 3

macroeconomic pathways of the saudi economy the challenge of global mitigation action versus the opportunity of national energy reforms abstract we analyse the mid term macroeconomic challenge to saudi arabia of a global low carbon transition reducing oil revenues versus the opportunity of national energy reforms we calibrate a compact dynamic recursive model of saudi arabia on original energy economy data to explore scenarios we first assess the consequences of oil prices declining from their levels in the new policies scenario nps of the iea to their levels in its sustainable development scenario sds by 2030 the saudi economy loses 1 4 gdp points 1 6 employment points and usd 504 billion trade surplus accumulation its cumulated public deficit rises to 92 8 of gdp national reforms gradually aligning saudi energy prices on international prices and inducing structural change of saudi activity away from energy intensive industries mitigate these costs if a share of the public income from energy price deregulation is directed to investment however they reduce the cumulated trade surplus and fail to control public deficit accumulation sensitivity analysis confirms the capacity of national energy reforms to mitigate the activity cost of global mitigation action but aggravates the threat of an escalating public deficit these results underline the importance of broader economic and fiscal reforms as part of the ambitious vision 2030 saudi initiative

imperfect competition and the effects of energy price increases on economic activity the authors show that modifying the standard neoclassical growth model by assuming that competition is imperfect makes it easier to explain the size of the declines in output and real wages that follow increases in the price of oil plausibly parameterized models of this type are able to mimic the response of output and real wages in the united states the responses are particularly consistent with a model of implicit collusion where markups depend positively on the ratio of the expected present value of future profits to the current level of output copyright 1996 by ohio state university press

gains from cartelisation in the oil market in this paper we ask whether opec still gains from cartelisation in the oil market despite low producer prices and a modest market share we apply two intertemporal equilibrium models of the global oil market one consisting of a cartel and a fringe and one describing a hypothetical competitive market comparing the outcome of these models we conclude that there are positive cartelisation gains of about 18 percent in the oil market in comparison with what pindyck 1978 found for the 1970s this may be considered as quite modest moreover we study whether the cartelisation gains to opec are altered by different moves by non opec producers or consumer countries generally we find that the relative cartelisation gains are unchanged one exception is exploration activities where we find that a major increase in non opec reserves could remove the cartelisation gains to opec completely in this case the opec countries could find themselves better off without the cartel

consumer bankruptcy a fresh start consumer bankruptcy provides partial insurance against bad luck but by driving up interest rates makes life cycle smoothing more difficult we argue that to assess this trade off one needs a quantitative model of consumer bankruptcy with three key features life cycle component idiosyncratic earnings uncertainty and expense uncertainty exogenous negative shocks to household balance sheets we find that transitory and persistent earnings shocks have very different implications for evaluating bankruptcy rules more persistent shocks make the bankruptcy option more desirable larger transitory shocks have the opposite effect our findings suggest the current us bankruptcy system may be desirable for reasonable parameter values jel d14 d91 k35

social security reform with impure intergenerational altruism abstract this paper studies the long run aggregate and welfare effects of eliminating social security in a quantitative dynamic general equilibrium life cycle model where parents and their children are linked by voluntary and accidental bequests social security in this model with impure altruism has a smaller effect on capital accumulation than in a pure life cycle model a bigger effect than in a model with two sided altruism the welfare gain of eliminating social security system under impure altruism is smaller than that in a pure life cycle model and bigger than that in a model with two sided altruism

the cyclical and secular behaviour of the labour input comparing efficiency units and hours worked summary a monthly labour input series designed to correct for the fact that all hours worked are not of the same quality is constructed and its properties compared with unadjusted hours worked this efficiency units series is constructed from bls data on hours worked and earnings by age and sex the cyclical fluctuations displayed by the efficiency units series are smaller on average than those displayed by hours worked although the difference is not large however the secular behaviour of the series is quite different hours worked per capita displays a significant positive trend while efficiency units per capita does not

unemployment in britain male unemployment in britain has risen from around 2 per cent in the 1950s to around 17 per cent in 1985 see figure 1 the figures are for male unemployment because there is no consistent series for women 1 even more remarkably unemployment has fallen in only three years out of the last twenty 1973 1978 and 1979 to account for this we need a model that explains both changes in the natural or non accelerating inflation rate of unemployment nairu and deviations from it we use a three equation supply side model centred on the labour market this has two main features the first concerns the determination of employment in the short run the labour demand function that we use cuts through the fruitless debate now raging especially in europe as to whether current unemployment is classical or keynesian according to the classical view employment is too high because real wages are too high according to the keynesian view real wages are not binding and unemployment is high because the product market does not clear with prices too high relative to nominal demand the whole debate is set in the framework of perfect competition yet in perfect competition prices are set by impersonal forces and it is not clear what could possibly stop prices clearing the market it is much more reasonable to think of prices as being set by imperfectly competitive firms existing prices being the best they can think of given the demand they face in this context firms demand for labour will depend on both the real product wage and the level of real aggregate demand this is the demand function we estimate and it conforms both to common sense and to the data however this does not imply that employment can be made to grow without limit by pumping up real demand for in the medium term when price surprises are eliminated our model determines three variables employment real wages and real demand on the basis of three equations an employment equation a price equation and a wage equation thus in the medium term there is a natural level of employment and corresponding to this a natural level of real aggregate demand the second key feature of our model concerns the medium term determination of unemployment in the medium term the planned mark up of wages over prices in wage settlements must be consistent with the mark up of prices over wage costs in employers pricing behaviour for if wage setters try to set real product wages higher than is consistent with employers pricing behaviour this generates ever increasing inflation thus the key to understanding unemployment in the medium term is the behaviour of wage setters if events occur that push them towards too high real wages then unemployment has to rise to offset these influences we shall call these influences wage pressure variables or push factors and they are clearly crucial in understanding unemployment the variables here include the social security system employment protection

social security and individual welfare precautionary saving borrowing constraints and the payroll tax this paper examines the impact of social security on national saving and individual welfare in the presence of realistic capital market imperfections market failure in the private provision of annuities and restrictions on borrowing against anticipated future wages the introduction of social security increases lifetime welfare and reduces national saving if borrowing restrictions are absent however the increase in individual welfare is reduced and in some cases eliminated when borrowing constraints are taken into consideration the substantial difference suggests the importance of reexamining the proportional payroll tax finance of social security copyright 1987 by american economic association

peak oil profiles through the lens of a general equilibrium assessment abstract this paper disentangles the interactions between oil production profiles the dynamics of oil prices and growth trends we do so through a general equilibrium model in which peak oil endogenously emerges from the interplay between the geological technical macroeconomic and geopolitical determinants of supply and demand under non perfect expectations we analyze the macroeconomic effects of oil production profiles and demonstrate that peak oil dates that differ only slightly may lead to very different time profiles of oil prices exportation flows and economic activity we investigate middle east s trade off between different pricing trajectories in function of two alternative objectives maximisation of oil revenues or households welfare and assess its impact on oecd growth trajectories a sensitivity analysis highlights the respective roles of the amount of resources inertia on the deployment of non conventional oil and short term oil price dynamics on peak oil dates and long term oil prices it also examines the effects of these assumptions on oecd growth and middle east strategic tradeoffs

the market evaluation of human capital the case of indentured servitude this paper examines the market for human capital created by the institution of indentured servitude in colonial america the indenture system allowed english emigrants to obtain passage to the colonies by selling claims on their future labor with the size of the debt approximately equal for all emigrants the length of the term for which a servant was bound is predicted to have varied inversely with expected productivity in the colonies analysis of two collections of contracts made in the seventeenth and eighteenth centuries supports the prediction age skill and literacy were negatively related to length of indenture women received shorter terms than men at young ages while servants bound for the west indies and those bound in periods of high colonial demand for labor also received reductions

can the world cut poverty in half how policy reform and effective aid can meet international development goals abstract poverty in the developing world will decline by about one half by 2015 if the trends of the 1990s persist most of this poverty reduction will occur in asia however while poverty will decline only slightly in africa effective aid could make a contribution to greater poverty reduction in lagging regions even more potent would be significant policy reform in these countries we develop a model of efficient aid in which flows respond to policy improvements that create a better environment for poverty reduction and effective aid we investigate scenarios of policy reform and efficient aid that point the way to how the world can cut poverty in half in every major region

aid policies and growth the authors of this paper use a new database on foreign aid to examine the relationships among foreign aid economic policies and growth of per capita gdp in panel growth regressions for 56 developing countries and 6 four year periods 1970 93 they find that the policies that have a great effect on growth are those related to fiscal surplus inflation and trade openness they construct an index for those three policies and have that index interact with foreign aid they have instruments for both aid and aid interacting with policies they find that aid has a positive impact on growth in developing countries with good fiscal monetary and trade policies in the presence of poor policies aid has no positive effect on growth this result is robust in a variety of specifications which include or exclude middle income countries include or exclude outliers and treat policies as exogenous or endogenous they examine the determinants of policy and find no evidence that aid has systematically affected policies either for good or for ill they estimate an aid allocation equation and show that any tendency for aid to reward good policies has been overwhelmed by donors pursuit of their own strategic interests in a counterfactual they reallocate aid reduce the role of donor interests and increasing the importance of policy such a reallocation would have a large positive effect on developing countries growth rates

fuel conserving and using production functions abstract this article compares eight production cost functions used or potentially useful for exploring how energy efficiency gains affect energy consumption we show the practitioner s choice of function can inadvertently pre determine results and make recommendations as to which functions are flexible enough to prevent this we also show pre selected factor substitution elasticities can similarly pre determine results to aid the comparison we decompose the energy consumption rebound effect into intensity and output income effects which also delivers insight into the mechanisms of rebound we conclude by recommending practitioners restrict themselves to either the gallant fourier or the generalized leontief symmetric generalized barnett cost functions as being sufficiently rebound flexible the translog cost function may be suitable given certain conditions and a particular form of the ces solow function is a possible but problematic candidate along the way the article provides a general methodology for similarly examining any arbitrarily defined constant returns to scale production or cost function

monetary compensations in climate policy through the lens of a general equilibrium assessment the case of oil exporting countries this paper investigates the compensations that major oil producers have claimed for since the kyoto protocol in order to alleviate the adverse impacts of climate policy on their economies the amount of these adverse impacts is assessed through a general equilibrium model which endogenizes both the reduction of oil exportation revenues under international climate policy and the macroeconomic effect of carbon pricing on middle east s economy we show that compensating the drop of exportation revenues does not offset gdp and welfare losses because of the time profile of the general equilibrium effects when considering instead compensation based on gdp losses the effectiveness of monetary transfers proves to be drastically limited by general equilibrium effects in opened economies the main channels of this efficiency gap are investigated and its magnitude proves to be conditional upon strategic and policy choices of the middle east this leads us to suggest that other means than direct monetary compensating transfers should be discussed to engage the middle east in climate policies

consumption over the life cycle facts from consumer expenditure survey data this paper uses consumer expenditure survey data and a seminonparametric statistical model to estimate life cycle profiles of consumption controlling for demographics cohort and time effects we construct age profiles for total and nondurable consumption as well as expenditure patterns for consumer durables special emphasis is placed on the comparison of different approaches to control for changes in demo graphics over the life cycle we find significant humps over the life cycle for total nondurable and durable expenditures changes in household size account for roughly half of these humps bootstrap simulations suggest that our empirical estimates are tight in that standard errors are small

an integrated production inventory model with imperfect production processes and weibull distribution deterioration under inflation abstract this study develops an integrated production and inventory model from the perspectives of both the manufacturer and the retailer the model assumes a varying rate of deterioration partial backordering inflation imperfect production processes and multiple deliveries the elapsed time until the production process shift is assumed to be arbitrarily distributed the discounted cash flow and classical optimization technique are used to derive the optimal solution a numerical example including the sensitivity analysis is given to validate the results of the production inventory model the integrated decision results in lower optimal joint cost compared with an independent decision by the manufacturer and the retailer

the household bankruptcy decision personal bankruptcy filings have risen from 0 3 percent of households per year in 1984 to around 1 35 percent in 1998 and 1999 transforming bankruptcy from a rare occurrence to a routine event lenders lost about 39 billion in 1998 due to personal bankruptcy filings but economists have little understanding of why households file for bankruptcy or why filings have increased so rapidly until very recently studying the household bankruptcy decision was very difficult because no household level data set existed that included information on bankruptcy filings in this paper we use new data from the panel study of income dynamics which includes information on bankruptcy filings to estimate a model of households bankruptcy decisions we find support for the strategic model of bankruptcy which predicts that households are more likely to file when their financial benefit from filing is higher our model predicts that an increase of 1 000 in households financial benefit from bankruptcy would result in a 7 percent increase in the number of bankruptcy filings our model also predicts that if the 1997 national bankruptcy review commission s proposed changes in bankruptcy exemption levels were implemented there would be a 16 percent increase in the number of bankruptcy filings each year but if the 100 000 cap on homestead exemptions recently passed by the u s senate were adopted our model predicts that there would be only a negligible effect on the number of filings we find little support for the nonstrategic model of bankruptcy which predicts that households file when adverse events occur which reduce their ability to repay finally controlling for state and time fixed effects our model shows that households are more likely to file for bankruptcy if they live in districts with higher aggregate filing rates

public versus private provision of liquidity is there a trade off abstract to what extent is public debt private liquidity much policy advice given in the aftermath of the financial crisis rests on the assumption that increasing public debt relaxes borrowing constraints of private households this is the case for ad hoc debt limits which are exogenous to public policy instead if debt limits are fully endogenous as e g in the case of the natural borrowing limit public debt has no impact we assume that borrowing limits arise because of limited contract enforceability and are therefore determined as equilibrium outcomes using an incomplete markets economy in which households are subject to uninsurable earnings shocks we show that public debt provides some liquidity but less so than it would if constraints were imposed ad hoc we show that generating borrowing constraints as an equilibrium outcome substantially alters the answers to other important questions such as for the welfare effects of government debt or its impact on real economic activity

segment shifts and capacity utilization in the u s automobile industry an important school of thought argues that sectoral shifts may account for a substantial portion of aggregate fluctuations e g david lilien 1982 fischer black 1987 steven davis 1987 events such as the oil shocks of the 1970 s exchange rate fluctuations and shifts in government spending have their direct effect on the composition of economic activity the sectoral shift literature argues that they may affect the level and the dynamics of output and employment as well the typical story is of a slowly functioning labor market after a sectoral shock search behavior matching problems and a time cost of switching sectors slow the reallocation of workers across sectors this focus however misses important elements of the reallocation problem as black 1987 has argued not only sector specific human capital but also complementary physical and managerial engineering organization etc capital must be reallocated or recreated in response to sectoral shocks if jobs are linked to capital then the slow adjustment of labor may be attributable in part to the sluggishness in the adjustment of capital this paper presents an empirical study of the impact of oil shock sectoral shifts within the u s automobile industry from an analytical perspective a sectoral shift is any event that raises desired output and employment in some sectors and lowers them in others for our purposes a sector is a size class of automobiles within the automobile industry we will be able to study two distinct questions first did the oil priceinduced shocks to the composition of demand interact with short run rigidities in supply to limit industry wide capacity utilization we will quantify the extent to which the changing composition of demand was reflected in a lower aggregate output level with obvious consequences for the employment of capital and of labor and for the return to firms knowledge capital our second question concerns the pace of the intermediate run adjustment to sectoral shocks how rapidly could capital and labor be reallocated to new demand conditions such considerations determine the impact of sectoral shocks on employment and capacity utilization dynamics

aid dutch disease and manufacturing growth abstract we examine the effects of aid on the growth of manufacturing using a methodology that exploits the variation within countries and across manufacturing sectors and corrects for possible reverse causality we find that aid inflows have systematic adverse effects on a country s competitiveness as reflected in the lower relative growth rate of exportable industries we provide some evidence suggesting that the channel for these effects is the real exchange rate appreciation caused by aid inflows we conjecture that this may explain in part why it is hard to find robust evidence that foreign aid helps countries grow

u s consumer bankruptcy choice the importance of general equilibrium effects abstract we study the implications of u s personal bankruptcy rules for resource allocation and welfare our analysis shows that general equilibrium considerations along with bankruptcy chapter choice and production matter crucially for the effects of policy reform contrary to previous work we find that completely eliminating bankruptcy provisions causes significant declines in output and welfare by reducing capital formation and labor input furthermore subjecting chapter 7 filers to means testing as suggested by recent legislative proposals would not improve upon current bankruptcy provisions and at best leave aggregate filings output and welfare unchanged however we do find that an alternative tightening of chapter 7 in the form of lower asset exemptions can increase economic efficiency

politics and the effectiveness of foreign aid abstract critics of foreign aid programs have long argued that poverty reflects government failure in this paper i test predictions for aid effectiveness based on an analytical framework that relates aid effectiveness to political regimes i find that aid does not significantly increase investment nor benefit the poor as measured by improvements in human development indicators but it does increase the size of government the impact of aid does not vary according to whether recipient governments are liberal democratic or highly repressive but liberal political regimes and democracies ceteris paribus have on average 30 lower infant mortality than the least free regimes this may be due to greater empowerment of the poor under liberal regimes even though the political elite continues to receive the benefits of aid programs an implication is that short term aid targeted to support new liberal regimes may be a more successful means of reducing poverty than current programs

debt constrained asset markets we develop a theory of general equilibrium with endogenous debt limits in the form of individual rationality constraints similar to those in the dynamic consistency literature if an agent defaults on a contract he can be excluded from future contingent claims markets trading and can have his assets seized he cannot be excluded from spot markets trading however and he has some private endowments that cannot be seized all information is publicly held and common knowledge and there is a complete set of contingent claims markets since there is complete information an agent cannot enter into a contract in which he would have an incentive to default in some state in general there is only partial insurance variations in consumption may be imperfectly correlated across agents interest rates may be lower than they would be without constraints and equilibria may be pareto ranked

will opec lose from the kyoto protocol a range of energy economy models forecast losses to members of the organisation of petroleum exporting countries opec should the kyoto protocol come into force these forecasts are a powerful influence in the united nations framework convention on climate change negotiations they are used by opec to advance the agenda on the impacts of response measures covertly arguing for compensation for lost oil revenues arising from implementation of the protocol this paper discusses this issue and explores the key assumptions of these models and their uncertainties assumptions about carbon leakage future availability of oil reserves substitution innovation and capital turnover are considered the paper suggests that losses will not affect opec countries equally and that these losses are not likely to be as substantial as the models forecast a range of policy measures are proposed to lessen any impact the protocol may have on opec

welfare implications of endogenous credit limits with bankruptcy this paper studies the aggregate welfare consequences of changes in the prescribed penalty for personal bankruptcy and in social insurance policies when borrowing limits may respond to these changes it uses a dynamic general equilibrium model of an exchange economy with incomplete markets and a continuum of agents the borrowing constraint and the risk of default are endogenous and the default penalty restricts an individual s access to the markets for a fixed period of time the effect on the stationary equilibrium of an exogenous reduction of 1 and 2 years in this exclusion period is explored quantitatively for comparison purposes the same experiment is carried out under the assumption made in related studies that the borrowing limit is fixed a small welfare loss follows in either case in contrast in a small open economy welfare may increase substantially but only if the borrowing constraint is endogenous similar results follow from an exogenous change in social policy that reduces individual income variability

two warehouse inventory models for deteriorating items with shortages under inflation abstract in this paper the two warehouse inventory problem for deteriorating items with constant demand rate and shortages under inflation is considered in contrast to the traditional deterministic two warehouse inventory model with shortages at the end of each replenishment cycle an alternative model in which each cycle begins with shortages and ends without shortages is proposed here the optimal solution not only exists but also is unique comparing these two two warehouse inventory models the study shows that the proposed model is less expensive to operate than the traditional one in the case of the inflation rate is greater than zero hence under the consideration of inflationary effect the proposed model is less expensive finally some numerical examples for illustration are provided

aid and performance a reassessment two visions of aid effectiveness and allocation are compared the first corresponding to the new aid paradigm argues that aid is only effective if domestic policies are appropriate the second in contrast argues that aid effectiveness depends on the external and climatic environment the worse this environment or the more vulnerable the recipient countries the greater the effectiveness of aid cross sectional econometric tests related to gdp growth on two 12 year pooled periods clearly favour the second view the two views can be reconciled through the principle of performance based aid allocation where performance is defined as outcomes adjusted for the impact of environmental factors performance can then be measured in several manners which are subject to comparison one approach would lead one to allocate more aid the worse the external environment is for a given policy and the better the policy is for a given environment