Two queries

AbstractWe consider the question whether two queries SAT are as powerful as one query. We show that if PNP[1]=PNP[2] then: Locally either NP=coNP or NP has polynomial-size circuits; PNP=PNP[1]; Σp2⊆Πp2/1; Σp2=UPNP[1]∩RPNP[1]; PH=BPPNP[1]. Moreover, we extend the work of Hemaspaandra, Hemaspaandra, and Hempel to show that if PΣp2[1]=PΣp2[2] then Σp2=Πp2. We also give a relativized world, where PNP[1]=PNP[2], but NP≠coNP

Monetary Policy, Credibility and Asymmetries : Small African Countries and the EMU Advent

As a country sets a pig of its currency, the monetary policy credibility it expects to gain implies that the anti-inflationary performance has to be as similar as possible to the anchor country one. Failing to attain this goal can lead to speculative attacks against the currency parity. This is an insight from models of credibility in monetary policy through fixed exchange rates regimes. In addition, multiple equilibria embedded in these models may cause speculative attacks rendering the efficiency of exchange rate regimes questionable. Contrary to this theoretical insight, the franc zone continues to work despite the disinflation process in the European Union that is likely to increase the level of constraint related the use of the euro as an anchor. In this paper, we show how the existence of particular arrangements in the Franc zone allows for getting a framework without multiple equilibria and insures the stability of the system. Moreover, we introduce two kinds of structural asymmetries relative to African economies to show that without the “operations account” mechanismn, the EMU advent is likely to have increased the constraint related to a peg on the euro, leading to a more restraining pegCredibility, Monetary Policy, Exchange Rate Regime, EMU, International Monetary System, Exchange Rates