Linear-quadratic Approximation of Optimal Policy Problems


Book Description

We consider a general class of nonlinear optimal policy problems involving forward-looking constraints (such as the Euler equations that are typically present as structural equations in DSGE models), and show that it is possible, under regularity conditions that are straightforward to check, to derive a problem with linear constraints and a quadratic objective that approximates the exact problem. The LQ approximate problem is computationally simple to solve, even in the case of moderately large state spaces and flexibly parameterized disturbance processes, and its solution represents a local linear approximation to the optimal policy for the exact model in the case that stochastic disturbances are small enough. We derive the second-order conditions that must be satisfied in order for the LQ problem to have a solution, and show that these are stronger, in general, than those required for LQ problems without forward-looking constraints. We also show how the same linear approximations to the model structural equations and quadratic approximation to the exact welfare measure can be used to correctly rank alternative simple policy rules, again in the case of small enough shocks.




NBER Macroeconomics Annual 2003


Book Description

The NBER Macroeconomics Annual presents pioneering work in macroeconomics by leading academic researchers to an audience of public policymakers and the academic community. Each commissioned paper is followed by comments and discussion. This year's edition provides a mix of cutting-edge research and policy analysis on such topics as productivity and information technology, the increase in wealth inequality, behavioral economics, and inflation.




Optimal Fiscal and Monetary Policy, Debt Crisis and Management


Book Description

The initial government debt-to-GDP ratio and the government’s commitment play a pivotal role in determining the welfare-optimal speed of fiscal consolidation in the management of a debt crisis. Under commitment, for low or moderate initial government debt-to-GPD ratios, the optimal consolidation is very slow. A faster pace is optimal when the economy starts from a high level of public debt implying high sovereign risk premia, unless these are suppressed via a bailout by official creditors. Under discretion, the cost of not being able to commit is reflected into a quick consolidation of government debt. Simple monetary-fiscal rules with passive fiscal policy, designed for an environment with “normal shocks”, perform reasonably well in mimicking the Ramsey-optimal response to one-off government debt shocks. When the government can issue also long-term bonds–under commitment–the optimal debt consolidation pace is slower than in the case of short-term bonds only, and entails an increase in the ratio between long and short-term bonds.




Designing a Simple Loss Function for Central Banks


Book Description

Yes, it makes a lot of sense. This paper studies how to design simple loss functions for central banks, as parsimonious approximations to social welfare. We show, both analytically and quantitatively, that simple loss functions should feature a high weight on measures of economic activity, sometimes even larger than the weight on inflation. Two main factors drive our result. First, stabilizing economic activity also stabilizes other welfare relevant variables. Second, the estimated model features mitigated inflation distortions due to a low elasticity of substitution between monopolistic goods and a low interest rate sensitivity of demand. The result holds up in the presence of measurement errors, with large shocks that generate a trade-off between stabilizing inflation and resource utilization, and also when ensuring a low probability of hitting the zero lower bound on interest rates.




The Theory of Economic Policy in a Strategic Context


Book Description

A new unified theory of economic policy which responds to conflicts between strategic public and private policymakers.




Macroeconomic Paradigms and Economic Policy


Book Description

An examination of macroeconomic policy, focusing on the relationship between free-market policies and government intervention.




Optimal Fiscal Adjustment under Uncertainty


Book Description

The paper offers a non-probabilistic framework for representation of uncertainty in the context of a simple linear-quadratic model of fiscal adjustment. Instead of treating model disturbances as random variables with known probability distributions, it is only assumed that they belong to some pre-specified compact set. Such an approach is appropriate when the decision maker does not have enough information to form probabilistic beliefs or when considerations for robustness are important. Solution of the model in the minimax sense when disturbance sets are ellipsoids is obtained and the application of the method is illustrated using the example of Portugal.




Macroeconomic Policy in Fragile States


Book Description

Setting macroeconomic policy is especially difficult in fragile states. Political legitimacy concerns are heightened, raising issues such as who the policymakers are, what incentives they face, and how the process of policymaking is likely to work under limited legitimacy and high uncertainty both about the macroeconomic environment as well as policy effectiveness. In addition, fragility expands the range of policy objectives in ways that may constrain the attainment of standard macroeconomic objectives. Specifically, in the context of fragility policymakers also need to focus on measures to mitigate fragility itself - i.e., they need to address issues such as regional and ethnic economic disparities, youth unemployment, and food price inflation. Socio-political developments around the world have thus pushed policymakers to broaden their toolkit to improve the effectiveness of macroeconomic management in the face of these constraints. The chapters in Macroeconomic Policy in Fragile States address these issues, both by giving an analytical context from which policymakers can build to answer the questions they face in fragile situations as well as by providing lessons drawn from empirical analyses and case studies. The first section of the volume discusses the interactions between political economy considerations and macroeconomic policymaking. The second section covers the private sector environment in fragile states. The third section focuses on macroeconomic policy, especially fiscal policy, monetary policy, exchange rate policy, external flows, and aid effectiveness. The last section explains the role of the IMF in fragile states and concludes by presenting case studies from the Middle East and from Sub-Saharan Africa. The contributors to the volume are economists and political scientists from academia as well as policymakers from international organizations and from countries affected by fragility.




Handbook of Monetary Economics Vols 3A+3B Set


Book Description

How have monetary policies matured during the last decade? The recent downturn in economies worldwide have put monetary policies in a new spotlight. In addition to their investigations of new tools, models, and assumptions, they look carefully at recent evidence on subjects as varied as price-setting, inflation persistence, the private sector's formation of inflation expectations, and the monetary policy transmission mechanism. They also reexamine standard presumptions about the rationality of asset markets and other fundamentals. Stopping short of advocating conclusions about the ideal conduct of policy, the authors focus instead on analytical methods and the changing interactions among the ingredients and properties that inform monetary models. The influences between economic performance and monetary policy regimes can be both grand and muted, and this volume clarifies the present state of this continually evolving relationship. Presents extensive coverage of monetary policy theories with an eye toward questions raised by the recent financial crisis Explores the policies and practices used in formulating and transmitting monetary policies Questions fiscal-monetary connnections and encourages new thinking about the business cycle itself Observes changes in the formulation of monetary policies over the last 25 years




Macroprudential Policy and Practice


Book Description

A guide to the latest theoretical developments in macroprudential policy, the newest tool in central banking policymaking circles.