Exact Results for 1D Kondo Lattice from Bosonization

We find a solvable limit to the problem of the 1D electron gas interacting with a lattice of Kondo scattering centers. In this limit, we present exact results for the problems of incommensurate filling, commensurate filling, impurity vacancy states, and the commensurate-incommensurate transition.Comment: 4 pages, two columns, Latex fil

The algebra of price stability

Prices

The federal funds rate as an indicator of monetary policy: evidence from the 1980s

Recently, several economists have argued that movements in the federal funds rate are a good proxy for changes in monetary policy. In this article, Nathan Balke and Kenneth Emery critically examine this view and the evidence supporting it. Using simple vector autoregressions, they find that before 1980 the correlations between the federal funds rate and other important macroeconomic variables are consistent with a traditional monetary policy interpretation of the federal funds rate. However, they show that after 1982 the relationships between the federal funds rate and other macroeconomic variables change significantly. Most important, the correlations between the federal funds rate and other macroeconomic variables observed during the 1980s are not as consistent with a traditional monetary policy view of the federal funds rate as they were before 1980. ; Balke and Emery's work highlights how relationships between important macroeconomic variables can change when institutions or policy regimes change. While the federal funds rate may still be a good indicator of monetary policy, its relationship with other important macroeconomic variables is now clearly different from what it was before 1980.Interest rates ; Economic indicators

Understanding the price puzzle

Recent developments in measuring the stance of monetary policy have highlighted an interesting puzzle--namely, that an unexpected tightening in monetary policy leads to an increase rather than a decrease in the price level. In this article, Nathan Balke and Kenneth Emery present evidence on the price puzzle and discuss possible explanations for it. ; Balke and Emery find that the most plausible explanation is that, during the 1960s and '70s, monetary policy was not implemented in a way that fully offset inflationary supply shocks. During this period, monetary policy would tighten in response to a supply shock but not by enough to prevent inflation from rising. In the data, therefore, contractionary policy is positively correlated with inflation. Since the early 1980s, however, the price puzzle has disappeared for either one, or both, of two reasons: the Federal Reserve has placed greater emphasis on achieving price stability, or there have been fewer inflationary supply shocks to the economy.Prices

Inflation and monetary restraint: too little, too late?

Inflation (Finance) ; Monetary policy

The three-dimensional BF Model with Cosmological Term in the Axial Gauge

We quantize the three-dimensional $BF$-model using axial gauge conditions. Exploiting the rich symmetry-structure of the model we show that the Green-functions correspond to tree graphs and can be obtained as the unique solution of the Ward-Identities. Furthermore, we will show that the theory can be uniquely determined by symmetry considerations without the need of an action principle.Comment: one reference added, transmission errors correcte

Stripe phases in high-temperature superconductors

Stripe phases are predicted and observed to occur in a class of strongly-correlated materials describable as doped antiferromagnets, of which the copper-oxide superconductors are the most prominent representative. The existence of stripe correlations necessitates the development of new principles for describing charge transport, and especially superconductivity, in these materials.Comment: 5 pp, 1 color eps fig., to appear as a Perspective in Proc. Natl. Acad. Sci. US