凯恩斯革命中的创新与继承

凯恩斯革命是从理论、政策、方法三个层面展开的。货币非中性论、货币供给外生论、对萨伊定理的彻底否定构成凯恩斯革命的理论基础;财政政策和货币政策是凯恩斯革命赖以实现的政策工具;对经济学研究对象的纠偏、破除传统的两分法和首创货币经济学是凯恩斯革命赖以完成的方法论。与此同时,《通论》内在逻辑上的不一致性,与经典学派崇尚经济自由传统的趋同,决定了凯恩斯革命中的继承。由于经济运行的常态是非充分就业均衡,《通论》必然具有永恒价值。     

Keynesian Chaos

This paper shows how nonperiodic fluctuations can emerge in the standard fix price macroeconomic model when induced investment is strong enough. Specific functional forms are used to illustrate the phenomenon and to compute numerical evidence that nonperiodic fluctuations need not be rare.     

Death and the Keynesian multiplier

The Blanchard-Yaari continuous-time model of overlapping generations is applied to a monetary economy with Keynesian unemployment. It is shown that a positive probability of death increases the short- and long-run multipliers of government spending on output. In the first example this is due to the government deficit being bond-financed, plus the failure of Ricardian equivalence which death implies. In the second, where the government budget remains balanced, it is due to the private accumulation of capital, which has a wealth effect on consumption. However, in the absence of death, this is negated by the higher lifetime tax burden.     

Poole in the New Keynesian model

We study the properties of alternative central bank targeting procedures within the standard New Keynesian model. We find that Poole's famous insights concerning the output stabilization properties of money and interest rate targeting obtain when intertemporal substitution is low. And that output volatility rankings do not induce similar welfare rankings. Unlike the popular presumption, money targeting always fares better for money demand shocks. For fiscal shocks, money targeting does better for low and worse for high degree of intertemporal substitution. The opposite pattern obtains for supply shocks.     

Keynesian uncertainty and the instability of beliefs

In an influential critique, Coddington (1982) argues that Keynes uses the theme of uncertainty in an opportunistic way in the General theory emphasizing it when it suits his purposes and ignoring it when it does not. This reading is examined in the light of Keynes's earlier Treatise on probability. The first part of the paper argues that Keynes's epistemology differs in important respects from the one Coddington is attacking, and in particular, that Keynes's account contains conceptions of uncertainty not considered by Coddington. The two premises of Coddington's argument are then assessed. These are: 1) that Keynes provides no account of the relative impact of uncertainty in different decision-making contexts; and 2) that uncertainty is not a sufficient condition for unstable beliefs about future outcomes of current (investment) decisions. It is argued that Coddington is mistaken in asserting 1) and, although 2) is correct in principle, that there is nevertheless a strong presumption that uncertainty does lead to unstable beliefs in the particular situations Keynes describes. The conclusion is that the connection between uncertainty and unstable beliefs cannot be regarded as either analytically destructive or somehow beside the point, even on Coddington's terms.     

Transition from the classical to the Keynesian Perspective

This paper intends to recast the IS-LM to an analytical framework that reflects, more pertinently than the conventional version, Keynes's central analytical message in his General Theory resulting from his secession from the classics. The secession is imagined to be a process of transition from a simple analytical framework of the classics to this recast form of the IS-LM. Moreover the arguments in the paper occasionally touch on certain misleading conventional views pertaining to the issues.     

Ricardian equivalence and the intertemporal Keynesian multiplier

We show that Keynesian multiplier effects can be obtained in dynamic optimizing models if one combines both price rigidities and a “non-Ricardian” framework where, due for example to the birth of new agents, Ricardian equivalence does not hold.     

Imports in Keynesian Models*

This paper examines two main problems relating to the introduction of imports in the simple Keynesian model. First, imports need to be made a function of the aggregate demand components rather than income. Second, unless one assumes that intermediate imports are zero the solution of the simple Keynesian model will provide miltipliers which Overstate the exogenous demand change for domestic product.