Using Bäcklund transformation the spectral property of the KP-I lump solution is completely analyzed. It is proved that the lump solution is nondegenerate and has Morse index one. As a consequence we show that it is orbitally stable.

This paper studies the optimal linear tax-transfer policy in an economy where agents di¤er in productivity and in genetic background, and where longevity depends on health spending and genes. It is shown that, if agents internalize imperfectly the impact of genes and health spending on longevity, the utilitarian social optimum can be decentralized with type-speci…c redistributive lump sum trans...

Using the standard real business cycle model with lump-sum taxes, we analyze the impact of fiscal policy when agents form expectations using adaptive learning rather than rational expectations (RE). The output multipliers for government purchases are significantly higher under learning, and fall within empirical bounds reported in the literature (in sharp contrast to the implausibly low values ...

Due to the use of distortionary taxation, many believe that real-world economies should attain a lower level of public expenditures than one might suspect from the analysis of arti cial models where lump-sum taxes are assumed to be available. The paper examines this popular hypothesis by means of the two-type self-selection model of income taxation. I provide su cient conditions for both a lowe...

Many people invest regularly in sinking funds that track stock market indices. When stock markets themselves sink significantly, as in the current credit crunch, investors face a decision as to whether they should continue paying into a falling fund, or switch payment to a risk-free deposit account until the market recovers. Most financial advice is to keep investing on the grounds that as the ...

An inchworm robotic insect is presented that can displace on a smooth horizontal surface. It consists of a piezoelectric unimorph and two custom-designed limbs. A two-module lumped-parameter model is formulated to assist in the desigdanalysis process. The geometry of deformation is analyzed first by superimposing the unirnorph ’s elastic deformation to a rigid-body rotation around the limb/grou...

Lumped element models for the frequency dependence of substrate parasitics in integrated circuits are evaluated. The frequency ranges for which these models are applicable have been identified. Two new models that are suitable for very high frequencies are also presented.

We analyze the investment decision of a ...rm that may complete a project either in one lump or in smaller parts at distinct points in time. The ...rm faces a trade-o¤ between the cost savings that arise when the project is completed in one go and the additional ‡exibility that arises when the ...rm is able to respond to resolving uncertainty by choosing optimal timing individually for each sta...

This paper proposes a general equilibrium model that aims at quantifying the distributive effects of anticipated inflation in an incomplete market economy with heterogeneous agents. Based on empirical evidence, this paper assumes a fixed cost to participate in financial markets, which in equilibrium generates a theory of money. Money is a return dominated asset, but also a costless mean to smoo...

This paper reconsiders the welfare costs of in‡ation and the welfare gains from …nancial intermediation in a heterogeneous-agent economy where money is held as a store of value (as in Bewley, 1980). Because of heterogeneous liquidity demand, transitory lump-sum money injections can have persistent expansionary e¤ects despite ‡exible prices, and such e¤ects can be greatly ampli…ed by the banking...