The result of Benhabib, Schmitt-Grohé, and Uribe (2001) is powerful because it relies only on three rather natural conditions: the Fisher equation, the convex Taylor rule, and the lower bound of the nominal interest rate. Their result is striking because the paper reveals the peril of the active Taylor rule, which has been shown to implement the target in a stable manner under various condition...

Daily monitoring of Mrk 421 in the X-ray and TeV bands during the first half of 2004 showed rapid flaring events above an elevated base flux level, culminating from March to May 2004 at an average flux level matching the highest detected flux state in 2001. Here we summarise the daily X-ray spectral variability observed with the RXTE-PCA instrument. We also explore the X-ray and TeV gamma-ray c...