We present a model with a complex and a real scalar fields and a potential whose symmetry is explicitly broken by Planck-scale physics. For exponentially small breaking, the model accounts for the period of inflation in the early universe and for the period of acceleration of the late universe or for the dark matter, depending on the smallness of the explicit breaking.

Over the past three years we have determined the basic features of the Universe – spatially flat; accelerating; comprised of 1/3 a new form of matter, 2/3 a new form of energy, with some ordinary matter and a dash of massive neutrinos; and apparently born from a burst of rapid expansion during which quantum noise was stretched to astrophysical size seeding cosmic structure. The New Cosmology gr...

We study the welfare cost of inflation in a general equilibrium life cycle model with growth, costly financial intermediation, and taxes on nominal quantities. We find a stationary equilibrium of the model matches a wide variety of facts about the postwar U.S. economy. We then calculate that the inflation policy of the monetary authority has welfare consequences for agents that are an order of ...

The case for a free-market commodity money as provided by a genuine gold standard is simple yet decisive. It is based on the insight that the root cause of inflation in the modern world is the almost absolute monopoly over the supply of money which all national governments possess within their respective political jurisdictions. That such an arrangement necessarily produces inflation is not dif...

----------------------------------------------------------------------------------------------------------------------------Using over 100 years of U.S. data, we find that the long-run effects of inflation on consumption, investment, and output are positive. Thus, models generating long-term negative effects of inflation on output and consumption (including endogenous growth and RBC models with...

Closed string tachyon condensation in spacetime generates potentials on the worldsheet that model two-dimensional inflationary cosmology. These models illustrate and elucidate a variety of aspects of inflation, in particular the generation of quantum fluctuations and their back-reaction on geometry. We exhibit a class of Liouville gravity models coupled to matter that can exhibit, for example: ...

Inflation targeting has become the predominant monetary approach across the globe. In this paper, we examine the inflation targeting experience in developing countries. We estimate the effects of inflation targeting on macroeconomic performance in these economies. The approach is based on the methodology applied by Pétursson (2005) which uses panel data to assess the effects of inflation target...

The EU acceding countries are supposed to adopt the Euro as soon as economic convergence is achieved. This paper offers a methodology to quantify the economic consequences of an acceding country’s EMU entrance. A small macroeconomic two-country model is specified and combined with two different monetary policy regimes: (i) national monetary policy, (ii) monetary union. The performance of the tw...

This study is about the earnings-replacement rate of the old-age benefit for the average worker in manufacturing who had average earnings throughout his career. It updates previously published data for earlier years and compares the replacement rate of the combined social security and private pension benefits for selected countries, in an attempt to show what a more complete benefit package mig...

Describing the nature of the trade-off between inflation and output or unemployment has long been difficult and controversial. The Friedman-Phelps hypothesis, that there is no long-run Phillips curve trade-off between inflation and unemployment, has clearly won over most macro-. economists, but the debate has continued over what, if any, trade-off remains. The subtle notion that an uncertain sh...