asymmetric forecast densities for u s macroeconomic variables from a gaussian copula model of cross sectional and serial dependence most existing reduced form macroeconomic multivariate time series models employ elliptical disturbances so that the forecast densities produced are symmetric in this article we use a copula model with asymmetric margins to produce forecast densities with the scope for severe departures from symmetry empirical and skew t distributions are employed for the margins and a high dimensional gaussian copula is used to jointly capture cross sectional and multivariate serial dependence the copula parameter matrix is given by the correlation matrix of a latent stationary and markov vector autoregression var we show that the likelihood can be evaluated efficiently using the unique partial correlations and estimate the copula using bayesian methods we examine the forecasting performance of the model for four u s macroeconomic variables between 1975 q1 and 2011 q2 using quarterly real time data we find that the point and density forecasts from the copula model are competitive with those from a bayesian

optimal social security in a dynastic model with investment externalities and endogenous fertility this paper studies optimal pay as you go social security with investment externalities positive bequests and endogenous fertility with an investment externality a competitive solution without social security suffers from under investment in capital and over reproduction of population we show the existence of time consistent optimal social security that improves welfare by reducing fertility and increasing capital intensity we also illustrate numerically that a small degree of this externality can justify the observed high ratios of social security spending to gdp

the gender gap fertility and growth changes in fertility have long been recognized as important correlates of economic growth with the relationship between the level of fertility and the level of income per capita being one of the strongest observable correlations in cross country data this paper examines the linkages between fertility and growth theory the structure of the model is presented in sections on production couples decision making system dynamics and steady state equilibria the first component of the model is that increases in capital per worker raise womens relative wages since capital is more complementary to womens labor input than to mens the second component is that increasing womens relative wages reduces fertility by raising the cost of children more than household income finally lower fertility raises the level of capital per worker a positive feedback loop generates demographic transition a rapid decline in fertility accompanied by accelerated output growth

tastes and technology in a two country model of the business cycle explaining international trade on international financial markets allows people to insure country specific risk and smooth consumption intertemporally equilibrium models of business cycles with trade on global financial markets typically yield international consumption correlations near one and excessive volatility of investment the authors incorporate nontraded goods in the model and find that the implications for aggregate consumption investment and the trade balance are consistent with business cycle properties of industrialized countries however the model driven by technology shocks alone yields counterfactual implications for comovements between consumption and prices at the sectoral level taste shocks produce price quantity relationships more consistent with the data copyright 1995 by american economic association

theoretical analysis regarding a zero lower bound on nominal interest rates this paper explores several issues concerning a possible zero lower bound zlb including its theoretical rationale the magnitude of effects of low sustained inflation on real interest rates the validity of analyzing monetary policy in models with no monetary variables and the dynamic stabilizing properties of taylor rules in a zlb context the most important argument however is that if the short nominal rate is immobilized at zero there nevertheless exists a route for monetary stabilization policy to be effective via the foreign exchange market its quantitative importance is examined in a calibrated optimizing open economy model

re examining the consumption wealth relationship the role of model uncertainty this paper discusses the consumption wealth relationship we use data on consumption assets and labor income and a vector error correction framework this framework defines a set of models that differ in the number of co integrating vectors the form of deterministic components and lag length further models can be defined through parametric restrictions and in particular interest centers on a weak exogeneity restriction that says that the co integrating residuals do not affect consumption and income directly key results in previous work relate to the roles of permanent and transitory shocks in driving wealth and how consumption responds to these shocks we investigate the robustness of these results to model uncertainty and argue for the use of bayesian model averaging we find that there is a large degree of model uncertainty whether this uncertainty has important empirical implications depends on the researcher s attitude toward the theory used to motivate a co integrating relationship between consumption assets and income if we work with models consistent with this theory and impose the weak exogeneity restriction we find precisely estimated results that show that permanent shocks have only a small role in driving assets and that the predominant transitory shocks have little effect on consumption these findings are consistent with the previous literature however if we work with a broader set of models and let the data speak we find that the exact magnitude of the role of permanent shocks is hard to estimate precisely thus although some support exists for the view that their role is small we cannot rule out the possibility that they have a substantive role to play copyright c 2008 the ohio state university

commodity trade and international risk sharing how much do financial markets matter abstract this paper evaluates the social gains from international risk sharing in some simple general equilibrium models with output uncertainty a simulation model calibrated to selected moments of u s and japanese data estimates the incremental loss from a ban on international portfolio diversification to be on the order of 0 20 percent of output per year even the theoretical gains from asset trade may disappear under alternative sets of assumptions on preferences and technology the paper argues that the small magnitude of potential trade gains may help explain the apparently inconsistent findings of empirical studies on the degree of international capital mobility

discretionary monetary policy and the zero lower bound on nominal interest rates abstract ignoring the existence of the zero lower bound on nominal interest rates one considerably understates the value of monetary commitment in new keynesian models a stochastic forward looking model with an occasionally binding lower bound calibrated to the u s economy suggests that low values for the natural rate of interest lead to sizeable output losses and deflation under discretionary monetary policy the fall in output and deflation are much larger than in the case with policy commitment and do not show up at all if the model abstracts from the existence of the lower bound the welfare losses of discretionary policy increase even further when inflation is partly determined by lagged inflation in the phillips curve these results emerge because private sector expectations and the discretionary policy response to these expectations reinforce each other and cause the lower bound to be reached much earlier than under commitment

a welfare based analysis of international monetary policy spillovers at the zero lower bound we study the welfare effects of international monetary policy spillovers at the zero lower bound focusing on the effects of forward guidance in a large economy foreign on its smaller trading partner home in scenarios motivated by the global financial crisis we find that foreign forward guidance has an overall prosper thy neighbor effect on the home economy as long as it increases foreign welfare this finding holds under alternative assumptions about exchange rate pass through or the degree of international financial integration however foreign forward guidance may worsen the trade off between the stabilization objectives of home monetary policy

domestic and foreign disturbances in an optimizing model of exchange rate determination abstract this paper analyzes the effects of various disturbances of domestic and foreign origin in a small open economy under imperfect capital mobility in which the behavioral relationships are divided from optimization by the private sector in this model the domestic economy jumps instantaneously to its new equilibrium following a change in either the domestic monetary growth rate or domestic fiscal policy in response to a disturbance in either the foreign interest rate or inflation rate the economy undergoes an initial partial jump towards its new equilibrium which it thereafter approaches gradually the implications of these results for exchange rate adjustments and the insulation properties of flexible exchange rates are discussed

social security retirement age and optimal income taxation it is often argued that implicit taxation on continued activity of elderly workers is responsible for the widely observed trend towards early retirement in a world of laissez faire or of first best efficiency there would be no such implicit taxation the point of this paper is that when first best redistributive instruments are not available because some variables are not observable the optimal policy does imply a distortion of the retirement decision consequently the inducement of early retirement may be part of the optimal tax transfer policy we consider a model in which individuals differ in their productivity and their capacity to work long and choose both their weekly labor supply and their age of retirement we characterize the optimal non linear tax transfer that maximizes a utilitarian welfare function when weekly earnings and the length of active life are observable while individuals productivity and health status are not observable c 2003 elsevier b v all rights reserved

time varying effect of oil market shocks on the stock market abstract a mixture innovation time varying parameter var model is used to examine the impact of structural oil price shocks on u s stock market return time variation is evident in both the coefficients and the variance covariance matrix the standard deviations of the demand side structural shocks reached forty year peaks during the global financial crisis and have remained high since in the real stock return equation the coefficient of global real economic activity has declined since the late 1990s and that of oil market specific demand oil shock has been lower since the early 1990s than before the structural oil shocks account for 25 7 of the long run variation in real stock returns overall with substantial change in levels and sources of contribution over time the contribution of shocks to global real economic activity to real stock return variation rose sharply to 22 in 2009 and remains 17 over 2009 2012 the contribution of oil market specific demand price shocks rose unevenly from 5 in the mid 1970s to about 15 in 2007 with a subsequent decline the contribution of oil supply shocks has trended downward from 17 to 5 over 1973 2012

on the evolution of the monetary policy transmission mechanism this paper investigates whether the monetary transmission mechanism has changed or whether apparent changes are due to changes in the volatility of exogenous shocks also the question of whether any changes have been gradual or abrupt is considered a mixture innovation model is used which extends the class of time varying vector autoregressive models with stochastic volatility the advantage of our extension is that it allows us to estimate whether where when and how parameter change is occurring our empirical results indicate that the transmission mechanism the volatility of exogenous shocks and the correlations between exogenous shocks are all changing

occbin a toolkit for solving dynamic models with occasionally binding constraints easily abstract the toolkit adapts a first order perturbation approach and applies it in a piecewise fashion to solve dynamic models with occasionally binding constraints our examples include a real business cycle model with a constraint on the level of investment and a new keynesian model subject to the zero lower bound on nominal interest rates compared with a high quality numerical solution the piecewise linear perturbation method can adequately capture key properties of the models we consider a key advantage of the piecewise linear perturbation method is its applicability to models with a large number of state variables

mortality decline and long run economic growth this paper examines the impacts of mortality decline on long run growth in a dynastic family two sector growth model with social security a rise in longevity has direct effects on fertility human capital investment and growth as well as indirect effects through increasing unfunded social security contributions both the direct and indirect effects depend on the relative strength of the tastes for the number and welfare of children and may have different signs the net effects of rising longevity on fertility tend to be negative but positive on human capital investment and growth c 2001 elsevier science s a all rights reserved

fertility intra generational redistribution and social security sustainability incorporating heterogeneity in preference to having children into an overlapping generations model of a small open economy we examine the effects of changes in the size of pay as you go payg social security on fertility choices of individuals and population growth of the economy it is shown that payg social security will raise population growth by increasing the number of individuals who have children and the number of children parents have if the system involves redistribution between retirees with different contributions whereas if it has no redistribution payg social security does not affect the fertility decisions of individuals fecondite redistribution intra generationnelle et durabilite de la securite sociale incorporant l heterogeneite des preferences pour avoir des enfants dans un modele d une petite economie ouverte avec des generations qui se chevauchent on examine les effets de changements dans l importance de la securite sociale par repartition sur les choix de fecondite des individus et sur la croissance de la population dans l economie on montre que cette forme de securite sociale augmente la croissance de la population en accroissant a la fois le nombre de personnes qui ont des enfants et le nombre d enfants que les parents choisissent d avoir si le systeme implique une redistribution entre les gens a la retraite qui ont fait des contributions differentes alors que si le regime n implique aucune redistribution le regime de securite sociale par repartition n affecte pas les decisions de fecondite des individus

stochastic search variable selection in vector error correction models with an application to a model of the uk macroeconomy this paper develops methods for stochastic search variable selection currently popular with regression and vector autoregressive models for vector error correction models where there are many possible restrictions on the cointegration space we show how this allows the researcher to begin with a single unrestricted model and either do model selection or model averaging in an automatic and computationally efficient manner we apply our methods to a large uk macroeconomic model

the zero interest rate bound and the role of the exchange rate for monetary policy in japan in this paper we study the role of the exchange rate in conducting monetary policy in an economy with near zero nominal interest rates as experienced in japan since the mid 1990s our analysis is based on an estimated model of japan the united states and the euro area with rational expectations and nominal rigidities first we provide a quantitative analysis of the impact of the zero bound on the effectiveness of interest rate policy in japan in terms of stabilizing output and inflation then we evaluate three concrete proposals that focus on depreciation of the currency as a way to ameliorate the effect of the zero bound and evade a potential liquidity trap finally we investigate the international consequences of these proposals

international business cycles world region and country specific factors the paper investigates the common dynamic properties of business cycle fluctuations across countries regions and the world we employ a bayesian dynamic latent factor model to estimate common components in macroeconomic aggregates output consumption and investment in a 60 country sample covering seven regions of the world the results indicate that a common world factor is an important source of volatility for aggregates in most countries providing evidence for a world business cycle we find that region specific factors play only a minor role in explaining fluctuations in economic activity we also document similarities and differences across regions countries and aggregates jel f41 e32 c11 c32

optimal monetary policy under commitment with a zero bound on nominal interest rates we determine optimal monetary policy under commitment in a forwardlooking new keynesian model when nominal interest rates are bounded below by zero the lower bound represents an occasionally binding constraint that causes the model and optimal policy to be nonlinear a calibration to the u s economy suggests that policy should reduce nominal interest rates more aggressively than suggested by a model without lower bound rational agents anticipate the possibility of reaching the lower bound in the future and this amplifies the effects of adverse shocks well before the bound is reached while the empirical magnitude of u s mark up shocks seems too small to entail zero nominal interest rates shocks affecting the natural real interest rate plausibly lead to a binding lower bound under optimal policy however this occurs quite infrequently and does not imply positive average inflation rates in equilibrium interestingly the presence of binding real rate shocks alters the policy response to non binding markup shocks

liquidity traps capital flows abstract motivated by debates surrounding international capital flows during the great recession we conduct a positive and normative analysis of capital flows when a region of the global economy experiences a liquidity trap capital flows reduce inefficient output fluctuations in this region by inducing exchange rate movements that reallocate expenditure towards the goods it produces restricting capital mobility hampers such an adjustment from a global perspective constrained efficiency entails subsidizing capital flows to address an aggregate demand externality associated with exchange rate movements absent cooperation however dynamic terms of trade manipulation motives drive countries to inefficiently restrict capital flows impeding aggregate demand stabilization

intergenerational trade longevity and economic growth we develop an overlapping generations model of endogenous growth in which human capital is the engine of growth and the generations are linked through material and emotional interdependencies within the family parents invest in their children to achieve both old age support care and emotional gratification and material support from children is determined through self enforcing implicit contracts we show that optimal intergenerational trade can then lead to maximization of growth opportunities our model produces a theory of the demographic transition linking longevity fertility and economic growth we also show that while population aging may raise the growth rate an increase in young age longevity is likely to produce a greater increase in the growth rate and a reduction in the fertility rate in a growth equilibrium these predictions and the model s implications concerning the behavior of private savings during the takeoff period appear consistent with empirical evidence

the effects of foreign shocks when interest rates are at zero in a two country dsge model the effects of foreign demand shocks on the home country are greatly amplified if the home economy is constrained by the zero lower bound on policy interest rates this result applies even to countries that are relatively closed to trade such as the united states departing from many of the existing closed economy models the duration of the liquidity trap is determined endogenously adverse foreign shocks can extend the duration of the trap implying more contractionary effects for the home country the home economy is more vulnerable to adverse foreign shocks if the neutral rate is low consistent with secular stagnation and trade openness is high

the optimal inflation rate in new keynesian models should central banks raise their inflation targets in light of the zero lower bound we study the effects of positive steady state inflation in new keynesian models subject to the zero bound on interest rates we derive the utility based welfare loss function taking into account the effects of positive steady state inflation and solve for the optimal level of inflation in the model for plausible calibrations with costly but infrequent episodes at the zero lower bound the optimal inflation rate is low typically less than two percent even after considering a variety of extensions including optimal stabilization policy price indexation endogenous and statedependent price stickiness capital formation model uncertainty and downward nominal wage rigidities on the normative side price level targeting delivers large welfare gains and a very low optimal inflation rate consistent with price stability these results suggest that raising the inflation target is too blunt an instrument to efficiently reduce the severe costs of zero bound episodes

pensions and fertility incentives this paper discusses the welfare implications of a pay as you go pension reform by introducing a child benefit in an endogenous fertility setting in the model of a small open economy higher fertility is associated with a reduction of lifetime labour supply the optimum share of fertility related pensions is always below unity but generally positive the former is true since individuals do not take into account the impact of their labour supply choice on the parent generation it is demonstrated that child allowances are equivalent to fertility related pensions as instruments to achieve the optimum allocation

the robustness and efficiency of monetary policy rules as guidelines for interest rate setting by the european central bank abstract this paper examines the implications of recent research on monetary policy rules for practical monetary policy making with special emphasis on strategies for setting interest rates by the european central bank ecb the paper draws on recent research and new simulations of a large open economy model to assess the efficiency of a simple benchmark rule in comparison with other proposed rules further it stresses new results on the robustness of monetary policy rules in which each rule that is optimal or good according to one model or researcher is tested for robustness by other researchers using different models because of the large increase in the number of economists focussing on econometric evaluation of monetary policy rules for the interest rate instrument and because of the parallel increase in the variety of models being developed for this purpose much more evidence is becoming available on the robustness of simple monetary policy rules for the interest rate than ever before

elderly labor supply and fertility decisions in aging population economies with a longer life expectancy individuals who plan to work when they are old may increase the number of their children therefore when individuals choose the time of retirement the fertility rate may not necessarily decline but even rise

the pay as you go pension system as fertility insurance and an enforcement device a paygo system may serve as insurance against not having children and as an enforcement device for ungrateful children who are unwilling to pay their parents a pension in fact the latter was bismarck s historic motive for introducing this system it is true that the paygo system reduces the investment in human capital but if it is run on a sufficiently small scale it may nevertheless bring about a welfare improvement if on the other hand the scale of the system is so large that parents bequeath some of their pensions to their children it is overdrawn and creates unnecessarily strong disincentives for human capital investment

optimal monetary policy at the zero interest rate bound what should a central bank do when faced with a weak aggregate demand even after reducing the short term nominal interest rate to zero to address this question we solve a central bank s intertemporal loss minimization problem in which the non negativity constraint on nominal interest rates is explicitly considered we find that the optimal path is characterized by policy inertia in the sense that a zero interest rate policy should be continued for a while even after the natural rate of interest returns to a positive level by making such a commitment the central bank is able to achieve higher expected inflation lower long term nominal interest rates and a weaker domestic currency in the adverse periods when the natural rate of interest significantly deviates from a steady state level

endogenous fertility and optimal population size pareto optimality which is the standard criterion of efficiency in general equilibrium models takes population size as given and therefore cannot be directly applied to analyze the question of optimal population size the criterion then for optimal population size must be based on a more restrictive definition of optimality this paper extends peter diamonds 1965 golden golden rule growth model by assuming that individuals derive utility from their own consumptionand from their own children offspring are assumed to consume resources before reaching adulthood the authors show that the optimal steady state utility yields a higher population growth rate when it converges to the golden rule allocation they then demonstrate that a voluntary social security program in which the size of the transfer to a particular agent is directly tied to his own fertility leads the competitive allocation to be identical to the allocation corresponding to the maximum of the steady state utility of the representative individual

were there regime switches in u s monetary policy working paper 2004 14 june 2004 abstract a multivariate model identifying monetary policy and allowing for simultaneity and regime switching in coefficients and variances is confronted with u s data since 1959 the best fit is with a model that allows time variation in structural disturbance variances only among models that also allow for changes in equation coefficients the best fit is for a model that allows coefficients to change only in the monetary policy rule that model allows switching among three main regimes and one rarely and briefly occurring regime the three main regimes correspond roughly to periods when most observers believe that monetary policy actually differed and the differences in policy behavior are substantively interesting though statistically ill determined the estimates imply monetary targeting was central in the early 80s but was also important sporadically in the 70s the changes in regime were essential neither to the rise in inflation in the 70s nor to its decline in the 80s jel classification e52 e47 c53 key words counterfactuals lucas critique policy rule monetary targeting simultaneity volatility model comparison i the debate over monetary policy change in an influential paper clarida gali and gertler 2000 cgg presented evidence that us monetary policy changed between the 1970 s and the 1980 s indeed that in the 70 s it was drastically worse they found that the policy rule apparently followed in the 70 s was one that when embedded in most stochastic general equilibrium models would imply non uniqueness of the equilibrium and hence vulnerability of the economy to sunspot fluctuations of arbitrarily large size their estimated policy rule for the later period on the other hand eliminated this indeterminacy these results are a possible explanation of the volatile and rising inflation of the 70 s and of its subsequent decline the cgg analysis has two important weaknesses one is that it fails to account for stochastic volatility us macroeconomic variables and particularly the federal funds rate have gone through periods of tranquility and of agitation with forecast error variances varying greatly from period to period ignoring such variation does not lead to inconsistent estimates of model parameters when the forecasting equations themselves are constant but it strongly biases toward a finding of changed parameters tests of the stability of the forecasting equations the other weakness is that the cgg analysis rests on powerful and implausible identifying assumptions they require that we accept that the response of the monetary authority to expected future inflation and output does not depend on the recent history of inflation money growth or output it is hard to understand why this should be so especially in the 70 s when monetarism was a prominent theme in policy debates congress was requiring reports from the fed of projected time paths of monetary aggregates and financial markets were reacting sensitively to weekly money supply numbers the requirement for existence and uniqueness of equilibrium in dynamic models is that the monetary policy rule show a more than unit response of interest rates to the sum of the logs of all nominal variables that appear on the right hand side of the reaction function if we force a particular measure of expected future inflation to proxy for all the nominal variables that actually appear independently in the reaction function we are bound to get distorted conclusions on the one hand because expected future inflation will be a noisy measure of the full set of nominal influences on policy we might get downward bias in our estimates from the usual errorsin variables effect on the other hand to the extent that expected future inflation like most expected future values shows less variation than current nominal variables we could find a mistaken scaling up of coefficients

inequality and growth why differential fertility matters we argue that inequality and growth are linked through differential fertility and the accumulation of human capital we build an overlapping generations model in which dynasties differ in their initial endowment with human capital growth the income distribution and fertility are endogenous due to a quantiy quality tradeoff families with less human capital decide to have more children and invest less in education when initial inequality is high large fertility differentials lower the growth rate of average human capital since poor families who invest little in education make up a large fraction of the population in the next generation a calibrated model shows that this fertility differential effect is quantitatively important we also provide empirical evidence to confirm the links between inequality differential fertility and growth suggested by the model

credible commitment to optimal escape from a liquidity trap the role of the balance sheet of an independent central bank we start from two empirical facts 1 central banks target cpi inflation 2 independent central banks are concerned about their balance sheet and the level of their capital the first fact makes it difficult for a central bank to implement the optimal escape from a liquidity trap because it makes a commitment to overshoot the inflation target not credible we show that the second fact helps to solve this credibility problem the optimal policy can take the form of a currency depreciation combined with a crawling peg a policy advocated by svensson as the foolproof way to escape from a liquidity trap jel e52 f31 f41 this paper starts from two empirical facts 1 central banks target infl ation measured by the consumer price index cpi 2 independent central banks are concerned about their balance sheet and the level of their capital we provide evidence for these facts below the first fact adds to the well known credibility problem of the optimal escape from a liquidity trap the second fact provides a mechanism through which the credibility problem can be solved and the optimal escape

a long run structural macroeconometric model of the uk a new modelling strategy that provides a practical approach to incorporating long run structural relationships suggested by economic theory in an otherwise unrestricted var model is applied to construct a small quarterly macroeconometric model of the uk estimated over 1965q1 1999q4 in nine variables domestic and foreign outputs prices and interest rates oil prices the nominal effective exchange rate and real money balances the aim is to develop a model with a transparent and theoretically coherent foundation tests of restrictions on the long run relations of the model are presented the dynamic properties of the model are discussed and monetary policy shocks identified

international real business cycles we ask whether a two country real business cycle model can account simultaneously for domestic and international aspects of business cycles with this question in mind we document a number of discrepancies between theory and data the most striking discrepancy concerns the correlations of consumption and output across countries in the data outputs are generally more highly correlated across countries than consumptions in the model we see the opposite

social security and endogenous fertility pensions and child allowances as siamese twins abstract this paper analyses public pensions and child support in a model with endogenous fertility we show that the individual fertility choice may not coincide with the social optimum due to the existence of external effects of children on society as a whole the market outcome without government intervention is efficient however as the externalities exactly cancel out in that case if the government wants to redistribute towards the old it cannot replicate the command optimum by merely applying lump sum transfers but rather needs a child allowance scheme to effectively alter the number of offspring finally we analyse whether a pareto improving social security reform is possible it is shown that merely reducing the payg scheme cannot be pareto improving but the introduction of a child allowance scheme can be

social security intergenerational transfers and endogenous growth in this paper the effects of social security in a simple model of endogenous growth with alternative motives of having children are analyzed it shows how the effects of social security depend on the size of the social security tax the motive to have children and the pattern of intergenerational transfers the pattern of intergenerational transfers itself however is shown to change with the social security tax rate when the social security tax is not too high social security increases per capita income growth and tends to enhance welfare