A comment on the role of prices for excludable public goods

Blomquist and Christensen [(2005). The role of prices for excludable public goods, International Tax and Public Finance, 12 ,61–79] argue that welfare is initially decreasing in the price of an excludable public good and that the case for a positive price for an excludable public good price is weak. We argue that this result follows from their particular characterization of the public good and that an alternative and equally reasonable characterization overturns their result. Hence, the policy case for a positive price on the public good is stronger than Blomquist and Christiansen suggest. JEL Classification H21 · H41     

Intangible investment and Ramsey capital taxation

The standard analysis of optimal fiscal policy aggregates different types of assets into a unique capital good and all types of capital taxes into a unique capital tax. This paper considers a disaggregated framework: an economy with corporate and dividend taxes, where firms invest in both tangible and intangible assets (which can be expensed or sweat). In our setup, firms can always respond to changes in the timing of taxation. We find that the optimal long-run policy features zero corporate taxes and positive dividend taxes, with labor and dividend taxes being identical. Moreover, the initial capital levy is relatively small.     

Optimal Mortgage Refinancing with Regime Switches

A model of rational mortgage refinancing is developed where the drift and volatility of interest rate process switch between two regimes. Because of the possibility of a regime shift, the optimal refinancing policy is characterized by the different threshold of interest differential for each regime. Numerical simulation demonstrates that the optimal refinancing threshold in each regime can be smaller or larger than the threshold under single-regime models. Finally, we evaluate the predictions of the model, based on the estimated parameters for a two-regime model to capture the evolution of the mortgage rates in the US. Our model can produce both late and early refinancing, which is consistent with the observed refinancing behavior. The views expressed in this paper are solely those of the authors and do not necessarily reflect official positions of the Sumitomo Trust and Banking Co., Ltd.     

Interest rate rules, inflation and the Taylor principle: an analytical exploration

Summary. The purpose of this article is to characterize optimal interest rate rules in the framework of a dynamic stochastic general equilibrium model, and notably to scrutinize the “Taylor principle”, according to which the nominal interest rate should respond more than one for one to inflation. This model yields explicit solutions for the optimal rule. We find that the elasticity of response depends on numerous factors, such as the degree of price rigidity, the autocorrelation of the underlying shocks, or which measure of inflation is used. In general the optimal elasticity of the interest rate with respect to inflation needs not be greater than one.Received: 6 November 2003, Revised: 17 August 2004 JEL Classification Numbers: E5, E52, E58.J.-P. Bénassy: I wish to thank Daniel Laskar and an anonymous referee for their perceptive comments on earlier drafts of this paper. Of course all remaining deficiencies are mine.     

磷化氢环流熏蒸杀虫最低密闭时间的研究

磷化氢环流是一个复杂的过程,既要掌握有效的浓度,又要维持足够的密闭时间.在一定磷化氢浓度下,一次性全部杀死粮内害虫的最佳密闭时间应等于施药后磷化氢浓度上升到杀虫有效浓度的时间 杀死该粮堆内害虫成虫和幼虫的时间 杀死成虫死亡前产出的卵在此环境中的孵化时间或存在的蛹的发育时间 杀死卵孵化出的幼虫和成虫的时间.实验证实,在粮温10-24℃、磷化铝3g/m3剂量下,采取环流熏蒸措施,杀死玉米象和赤拟谷盗最低需要21d,杀死谷蠢需要26～28d.     

几何布朗运动市场中的最优变现策略研究

利用相对价格冲击函数的Box-Cox变换和存在比例交易费用的线性函数,研究了非瓦尔拉斯均衡金融市场上风险资产的价格变现策略,当资产价格变化服从几何布朗运动时,资产变现时间内生情形下投资者最优变现策略问题可以转化为具有随机跳出时间的随机最优控制,通过对带有广义狄利克雷边界条件的贝尔曼方程的粘性求解,可以实现最优变现策略。