What to stabilize in the open economy*

We consider the question how “best” to maintain price‐level stability in an open economy, and evaluate three possible policy choices: (a) a constant money growth rate rule; (b) a fixed exchange rate; and (c) a policy of explicit commitment to a price‐level target. In each case we assume that policy is conducted by injecting reserves into or withdrawing reserves from the “banking system.” In evaluating the three regimes, we adopt the criterion that the “best” policy should leave the least scope for indeterminacy and “excessive” economic volatility. In a steady‐state equilibrium, the choice of regime is largely irrelevant; any steady‐state equilibrium under one regime can be duplicated by an appropriate choice of the “control” variable under any other regime. However, we show that the sets of equilibria under the three regimes are dramatically different. When all countries follow the policy of fixing a constant rate of money growth, there are no equilibria displaying endogenously arising volatility and there is no indeterminacy of equilibrium. Under a regime of fixed exchange rates, indeterminacies and endogenously arising fluctuations are impossible if and only if the country with the low “reserve‐to‐deposit” ratio is charged with maintaining the fixed rate. Finally, when one country targets the time path of its price level, under very weak conditions, there will be indeterminacy of equilibrium and endogenously arising volatility driven by expectations.     

MONETARY POLICY REGIME SWITCHES AND MACROECONOMIC DYNAMICS*

This article considers the determinacy and distributional consequences of regime switching in monetary policy. Although switching in the inflation target does not affect determinacy, switches in the inflation response can cause indeterminacy. Satisfying the Taylor principle period by period is neither necessary nor sufficient for determinacy when inflation responses switch; indeterminacy can arise if monetary policy responds too aggressively to inflation in the active regime. Inflation target switches primarily impact the level of inflation, whereas inflation response switches primarily impact the volatility. Expecting an inflation target switch has minor effects on volatility, whereas expecting an inflation response switch raises volatility more substantially.     

Superneutrality, indeterminacy and endogenous growth

In this paper, we explore the possibility of having money as a source of indeterminacy in endogenous growth models. We adopt the simple Ak model of endogenous growth to be the main analytical vehicle whose balanced growth paths do not display local indeterminacy. Money is introduced via either a general cash-in-advance (CIA) constraint or a pecuniary transactions costs (PTC) technology. It is shown that local indeterminacy of the dynamics is due to the presence of an intertemporal substitution effect on capital accumulation that works against and dominates the conventional inflation effect of Tobin [1965, Money and economical growth. Econometrica 33(4), Part 2, 671]. If money is growth-rate superneutral, then the intertemporal substitution effect is absent so that local indeterminacy cannot occur. Finally, the strength of the intertemporal substitution effect depends positively on the intertemporal elasticity of substitution in consumption.     

短期经济波动如何影响长期增长趋势?

短期经济波动如何影响长期经济平均增长趋势已成为一个新的研究热点。本文研究我国省际数据发现,波动性对长期增长趋势有显著影响:1978年前,波动性与平均增长呈负相关的特征在多数省份出现;1978年后,两者关系主要表现为正相关。本文通过建立内生随机增长模型,研究波动与增长之间的内在关联,提出了实际波动与增长关系的一种合理解释。模型的基本思想是:人力资本形成过程分为自然形成和主观形成,教育投入等决定主观形成过程的因素的多少是决定波动性如何影响长期经济增长方向的关键。当教育投入较高,以致主观过程占优时,波动性对长期增长趋势有正效应;反之,当自然过程占优时,波动性对平均增长有负效应。模型结论与建国后的发展历史相印证:1978年前,生产水平低,教育投入少,人力资本形成中干中学比例占优,因而波动性同增长呈负相关;1978年恢复高考后,教育正常化,生产发展,教育投入增加,因而波动性与增长逐渐呈现正相关。     

Imperfect competition and indeterminacy of aggregate output

This paper shows imperfect competition can lead to indeterminacy in aggregate output in a standard DSGE model with imperfect competition. Indeterminacy arises in the model from the composition of aggregate output. In sharp contrast to the indeterminacy literature pioneered by Benhabib and Farmer [J. Benhabib, R. Farmer, Indeterminacy and increasing returns, J. Econ. Theory 63 (1) (1994) 19-41] and Gali [J. Gali, Monopolistic competition, business cycles, and the composition of aggregate demand, J. Econ. Theory 63 (1) (1994) 73-96], indeterminacy in our model is global; hence it is more robust to structural parameters. In addition, sunspots in our model can be autocorrelated. The paper provides a justification for exogenous variations in desired markups, which play an important role as a source of cost-push shocks in the monetary policy literature. Our model outperforms a standard RBC model driven by technology shocks in several dimensions, including the volatility of labor market and the hump-shaped output dynamics.     

Education and growth with endogenous debt constraints

When future human capital cannot be alienated, households are allowed to borrow up to the point where it is in their own interest not to default. In such a framework, endogenous borrowing limits arise as the outcome of individual rationality constraint. In a model where education is the engine of growth, we show that endogenous borrowing constraints imply global indeterminacy. Comparing outcomes across the various equilibria we show that the relation between growth and yields is hump-shaped. Maximum growth can arise in an equilibrium with binding borrowing constraints, specially if the elasticity of human capital to education spending is large. Deepening financial markets promotes long-run growth in the case of a poverty trap, but not necessarily otherwise. On the methodological side, our approach stresses the importance of studying borrowing limits in general equilibrium, not only in small open economies. Philippe Michel passed away on July 22, 2004. His death is a great loss for his friends and for the overlapping generations and optimal control community.     

Aid, Volatility, and Growth Again: When Aid Volatility Matters and When it Does Not

In previous papers the authors have argued that aid is likely to mitigate the negative effects of external shocks on economic growth (i.e. that aid is more effective in countries which are more vulnerable to external shocks). Recently an important debate has emerged about the possible negative effects of aid volatility itself. However, the cushioning effect of aid may involve some volatility in aid flows, which then is not necessarily negative for growth. In this paper the authors examine to what extent the time profile of aid disbursements may contribute to an increase or a decrease of aid effectiveness. They first show that aid, even if volatile, is not clearly as pro-cyclical as is often argued, and, even if pro-cyclical, is not necessarily destabilizing. They measure aid volatility by several methods and assess pro-cyclicality of aid with respect to exports, thus departing from previous literature, which usually assess pro-cyclicality of aid with respect to national income or fiscal receipts. The stabilizing/destabilizing nature of aid is measured by the difference in the volatility of exports and the volatility of the aid plus export flows. Then, in order to take into account the diversity of shocks to which aid can respond, they consider the effect of aid on income volatility and again find that aid is making growth more stable, while its volatility reduces this effect. They finally show through growth regressions that the higher effectiveness of aid in vulnerable countries is to a large extent due to its stabilizing effect.     

ENDOGENOUS TIME PREFERENCE,INTEREST‐RATE RULES,AND INDETERMINACY*

This paper extends the Benhabib et al. flexible‐price, money‐in‐the‐utility‐function model by considering endogenous time preference and re‐examines equilibrium indeterminacy in response to alternative interest‐rate rules. We show that either an active or a passive interest‐rate feedback rule can generate local indeterminacy even if consumption and real money balances are Edgeworth independent. This result is in sharp contrast to that in the related literature. We also find that in the presence of endogenous time preference, local indeterminacy may occur regardless of whether the monetary policy is based on the interest‐rate feedback rule or money growth‐rate targeting.     

Policy volatility and growth

The paper aims to examine how fiscal and monetary volatility might affect the balanced economic growth rate using a standard monetary growth model characterized by nominal wage rigidity and productive public spending. The model shows that any type of shock — monetary or fiscal — can generate either a negative or positive relationship between short-run volatility and long-run growth, critically depending on the size of government and the elasticity of output with respect to labor/capital. In particular, given the labor income share, it shows that excessive government spending may cause the impact of fiscal volatility on long-run growth to turn from positive to negative. In addition, a rise in the volatility of the monetary shock is capable of generating either an increase or decrease in the mean of growth. With the range of the labor share values in reality, the model produces results consistent with the fact that the relationship between volatility and growth is generally found empirically to be more negative in developing than in developed countries. The model can be seen as a further explanation for the ambiguous empirical evidence in the existing literature.     

Fiscal policy and indeterminacy in models of endogenous growth

This paper investigates the dynamic behavior of two-sector models of endogenous growth with sector-specific external effects, and government expenditure financed by distortionary taxation. When this type of external effect is combined with a sufficient degree of capital taxation in a Lucas-Uzawa endogenous growth model, continua of equilibria will emerge in the region of the balanced growth paths. By contrast, indeterminacy is not possible when either sector-specific external effects or factor taxation are added to the model in isolation. In the second part of the paper, we demonstrate that if labor supply is endogenous, indeterminacy can be consistent with much lower degrees of increasing returns to scale. Furthermore, certain types of fiscal policy will be associated with multiple balanced growth paths and the existence of a poverty trap. Finally, in the last part of the paper, we demonstrate that if physical capital is employed in both sectors of the economy, indeterminacy will emerge for varying combinations of factor taxation and external effects, even when returns to scale are constant at the social level.     

Can consumption habit spillovers be a source of equilibrium indeterminacy?

This paper investigates whether the external consumption habit can be a source of indeterminacy in a one-sector growth model when the labor supply is elastic. When there is a proper habit effect with a positive intertemporal elasticity of substitution, we find that the model exhibits indeterminacy if the coefficient of the habit formation is sufficiently large that allows for a substantial impact of current consumption on the habit. Indeterminacy arises even though the elasticity of the Frisch labor supply is positive and the elasticity of the labor demand in negative. In a calibrated version, we find that indeterminacy is empirically plausible when the habit effect is negative that features the “catching up with the Joneses” effect. Under given “catching up with the Joneses” effects, the external consumption habit can be a source of indeterminacy even if more than a half of the external consumption habit comes from past average consumption.     

Volatility in asset prices and long-run wealth effect estimates

We argue that the equation commonly used in the estimation of the wealth effect on consumption might be unsuitable for that purpose. In particular, if the usual assumptions are employed, the derivation of the equation implies that the wealth effect is indeterminate. Furthermore, it implies that the estimate of the wealth effect should decrease when asset wealth volatility increases. Estimation of a Markov-switching model of the usual long-run aggregate consumption equation provides evidence favourable to the indeterminacy hypothesis.     

(In)determinacy, increasing returns, and the optimality of the Friedman rule in an endogenously growing open economy

This paper sets up a monetary endogenous growth model with Benhabib–Farmer production externalities for an open economy, and then uses it to investigate the possibility of indeterminacy. Moreover, the paper examines how the monetary authorities will set its optimal anchor of the money growth rate from the viewpoint of welfare maximization. Several main findings emerge from the analysis. First, when investment does not involve adjustment costs, the monetary equilibrium is locally determinate regardless of the strength of the labor externality and the extent of world capital market imperfections. Second, in the presence of investment adjustment costs, the monetary equilibrium may exhibit indeterminacy when the aggregate increasing returns-to-scale in production is sufficiently strong. Third, in the presence of world capital market imperfections, the Friedman rule of a zero nominal interest rate fails to be optimal. Fourth, in the face of perfect world capital markets, the optimal nominal money growth rate is maintained at the rate that is conformable to the Friedman rule, regardless of whether investment involves adjustment costs or not.     

Multiple steady states,indeterminacy, and cycles in a basic model of endogenous growth

The goal of this paper is to demonstrate that a basic model of endogenous growth with learning by doing may produce a rich array of outcomes. Starting point of our analysis is the Romer (1986a) approach. In contrast to Romer, however, we assume that one unit of investment shows different effects concerning the building up of physical and human capital, so that these variables cannot be merged into one single variable. With this assumption, it can be shown that multiple steady states, indeterminacy of equilibria, and persistent cycles may result in our model.     

Declining output volatility in Germany: impulses,propagation, and the role of monetary policy

The decline in output volatility in Germany is analysed. A lower level of variance in an autoregressive model of output growth can be either due to a change in the structure of the economy (a change in the propagation mechanism) or a reduced error term variance (reduced impulses). In Germany the decline output volatility is due to a decline in the persistence of the growth process. This is in contrast to the US results, where a break in the variance seems to dominate the decline in persistence. A change in the conduct of monetary policy (the establishment of another monetary policy regime) could be part of an explanation for the change in propagation. Stochastic simulations with a New Keynesian DSGE model support the hypothesis.     

Short-sighted managers and learnable sunspot equilibria

This paper assumes that firm managers make choices over a finite horizon while households plan over an infinite horizon. Following Shea (2013), I assume that labor exhibits firm-specific learning by doing so that newly employed labor is less productive than experienced labor. In the model, optimization requires that firm managers make conjectures about how their choices affect the labor demand choices of their successors. The model yields two steady states; one where the firm manager behaves as if she cares only about the present period and another where she is forward looking. The former (myopic) steady state usually exhibits higher output than the non myopic steady state. The non-myopic steady state also exhibits two regions of indeterminacy where extraneous, self-fulfilling expectational errors add volatility. One of these regions of indeterminacy is usually stable under adaptive learning while the other never is stable under learning.     

Corruption,growth, and growth volatility

While the existing studies focus on the corruption–growth relationship, this paper introduces a new focus involving corruption and growth volatility. The Ehrlich–Lui (1999) framework provides the theoretical background of the paper, which produces testable hypotheses regarding the corruption–growth and the corruption–growth volatility relationship. The cross-section dataset that is used in the empirical analysis contains 121 developed and developing countries. In terms of the relationship between the governance-related variables and growth rates, only corruption control and government effectiveness significantly and adversely affect the average growth rate. Regarding the relationship between growth volatility and governance-related variables, the results suggest that higher corruption control, expropriation risk control, government effectiveness, and government consumption decrease growth volatility.     

Knightian Uncertainty in Financial Markets: An Assessment

If information is too vague and imprecise to be summarized by a unique additive probability measure, an agent faces Knightian uncertainty or ambiguity rather than risk. Under Knightian uncertainty, an agent's beliefs may be represented by a capacity or a set of additive probabilities. It is proved that an agent's attitude towards ambiguity has a crucial role in asset price determination and portfolio choice. Knightian uncertainty attitude provides an alternative explanation of financial market failures and enables puzzles to be solved, such as market breakdowns, price indeterminacy and volatility, bid and ask spreads, portfolio inertia, violation of call and put parity.
(J.E.L.: D81, G11, G12).     

A Characterization of the Dynamical System in a Two-sector Overlapping-generations Model: The Case of Unbounded Growth

This paper characterizes perfect-foresight equilibria in a two-sector overlapping-generations economy for the case of unbounded growth. The analysis demonstrates that gross substitutability in consumption is not sufficient to ensure the determinacy of equilibrium. Unlike Boldrin and Rustichini (1994), indeterminacy of equilibria can arise within the framework of an overlapping-generations model with convex technology. The finite time horizon of agents is the source of such indeterminacy.
JEL Classification Number: 041.     

Income effects and indeterminacy in a calibrated one-sector growth model

This note analyzes how the indeterminacy of competitive equilibrium in one-sector growth models depends on the magnitude of the households' income effect on the demand for leisure. Since I am interested in quantitatively characterizing regions of indeterminacy, I use the Jaimovich and Rebelo [N. Jaimovich, S. Rebelo, Can news about the future drive the business cycle? Mimeo, Northwestern University, 2007] preferences that span a wide range of income effect values. I find that indeterminacy can occur for levels of aggregate-returns-to-scale that are well within recent empirical estimates. For these regions of indeterminacy, the model, when driven solely by sunspot shocks, generates second-moment properties that are consistent with the U.S. data at the business cycle frequency.