With non-controllable auto-regressive shocks, the welfare of Ramsey optimal policy is the solution of a single Riccati equation of a linear quadratic regulator. The existing theory by Hansen and Sargent (2007) refers to an additional Sylvester equation but miss another equation for computing the...

This paper aims at providing macroeconomists with a detailed exposition of the New Keynesian DSGE model. Both the sticky price version and the sticky information variant are derived mathematically. Moreover, we simulate the models, also including lagged terms in the sticky price version, and...

The optimal control literature traditionally analyzes linear-quadratic Gaussian (LQG) formulations of macroeconomic policy design where policy planers seek to minimize the distance between a direct target vector y and a vector of aspiration levels y*, using a suitably dimensioned matrix M as a...

We study identiÞcation in a class of three-equation monetary models. We argue that these models are typically not identiÞed. For any given exactly identiffed model, we provide an algorithm that generates a class of equivalent models that have the same reduced form. We use our algorithm to...

We study identification in a class of three-equation monetary models. We argue that these models are typically not identified. For any given exactly identified model, we provide an algorithm that generates a class of equivalent models that have the same reduced form. In our first two examples we...

We derive necessary and suffcient conditions for simple monetary policy rules that guarantee equilibrium determinacy in the New Keynesian monetary model. Our modeling framework is derived from a fully specified optimization model that is still amenable to analytical characterisation. The...

The paper examines the role of fiscal and monetary policy on the dynamics of monetary expansion in a macroeconomy. Its microeconomic structure defined by producers with neoclassical production functions, heterogeneous OLG consumers, and a stationary fiscal and monetary policy induces a...

I explore alternative credit policies in a theoretical model where (i) money is necessary as a means of payment, (ii) there is a shortage of liquidity that a central bank addresses through the extension of credit, (iii) money is necessary to repay debts, and (iv) the incentives to default are...

Based on an experimental analysis of a simple monetary economy we argue that a monetary system is more stable than one would expect from individual rationality. We show that positive reciprocity stabilizes the monetary system, provided every participant considers the feedbacks of his choice to...

We study discretionary monetary policy in an economy where economic agents have quasi-hyperbolic discounting. We demonstrate that a benevolent central bank is able to keep inflation under control for a wide range of discount factors. If the central bank, however, does not adopt the household's...