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.

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.

Continued progress in reducing advanced economy deficits and a gradually improving external environment have lowered short-term fiscal risks, according to this issue, but global prospects nevertheless remain subdued, and many advanced economies face a lengthy, difficult, and uncertain path to fiscal sustainability. Though many advanced economies are now close to achieving primary surpluses that will allow them to stabilize their debt ratios, this is only a first step, as merely stabilizing advanced economy debt at current levels would be detrimental to medium- and longer-term economic prospects. The key elements of the required policy package are well known: foremost among them is setting out—and implementing—a clear and credible plan to bring debt ratios down over the medium term. Debt dynamics have remained relatively positive in most emerging market economies and low-income countries, and most plan to continue to allow the automatic stabilizers to operate fully, while pausing the underlying fiscal adjustment process. Those with low general government debt and deficits can afford to maintain a neutral stance in response to a weaker global outlook. But countries with relatively high or quickly increasing debt levels are exposed to sizable risks, especially once effective interest rates rise as monetary policy normalizes in the advanced economies and concessional financing from advanced economies declines. The widespread use of energy subsidies makes commodity prices an additional source of vulnerability in many emerging market and low-income economies; subsidy reform, higher consumption taxes, and broadening of tax bases would help support consolidation efforts.

This paper critically reviews recent work regarding the sustainability of public debt. It argues that Debt Sustainability Analyses (DSAs) should be more than mere mechanical simulation exercises. Instead, a DSA should be linked to some objective regarding the distribution of fiscal burdens and distortions over time (in the tradition of Barro’s 1979 tax smoothing objective). The paper discusses objective functions that yield simple and transparent fiscal policy rules.

The paper explores the extent to which the pressure of debt service on other spending items may push governments to embark on fiscal consolidation beyond what is strictly necessary to secure solvency. The empirical analysis identifies thresholds of interest bill indicators beyond which governments appear to shift to policies aimed at durably curbing the debt trajectory. Hence, in the current context of high inherited public debts, countries experiencing rising borrowing costs and interest payments would be more likely to enact more aggressive fiscal consolidations than warranted by strict solvency concerns. Conversely, those benefiting from persistently low interest rates despite rising debt stocks would likely opt for a more gradual fiscal consolidation path than what solvency considerations would normally dictate.

Libya is highly dependent on exhaustible and volatile hydrocarbon resources, which constitute the bulk of government revenues. Although resource wealth provides the means to promote socio-economic development, procyclical fiscal policies threaten macroeconomic stability as well as fiscal sustainability and intergenerational equity. In three parts, this paper provides an assessment of the cyclically adjusted fiscal stance, analyzes fiscal sustainability according the permanent income framework, and simulates various fiscal policy rules with the objective of developing a rule-based fiscal strategy that would delink the economy from oil price fluctuations, improve the management of resource wealth, and safeguard macroeconomic stability.

The scope of this volume is primarily to analyze from different methodological perspectives similar valuation and optimization problems arising in financial applications, aimed at facilitating a theoretical and computational integration between methods largely regarded as alternatives. Increasingly in recent years, financial management problems such as strategic asset allocation, asset-liability management, as well as asset pricing problems, have been presented in the literature adopting formulation and solution approaches rooted in stochastic programming, robust optimization, stochastic dynamic programming (including approximate SDP) methods, as well as policy rule optimization, heuristic approaches and others. The aim of the volume is to facilitate the comprehension of the modeling and methodological potentials of those methods, thus their common assumptions and peculiarities, relying on similar financial problems. The volume will address different valuation problems common in finance related to: asset pricing, optimal portfolio management, risk measurement, risk control and asset-liability management. The volume features chapters of theoretical and practical relevance clarifying recent advances in the associated applied field from different standpoints, relying on similar valuation problems and, as mentioned, facilitating a mutual and beneficial methodological and theoretical knowledge transfer. The distinctive aspects of the volume can be summarized as follows: Strong benchmarking philosophy, with contributors explicitly asked to underline current limits and desirable developments in their areas. Theoretical contributions, aimed at advancing the state-of-the-art in the given domain with a clear potential for applications The inclusion of an algorithmic-computational discussion of issues arising on similar valuation problems across different methods. Variety of applications: rarely is it possible within a single volume to consider and analyze different, and possibly competing, alternative optimization techniques applied to well-identified financial valuation problems. Clear definition of the current state-of-the-art in each methodological and applied area to facilitate future research directions.

This paper first attempts to quantify the natural resource wealth of Suriname from the perspective of its impact on the fiscal position, and then assesses the fiscal sustainability gap in that context. It then presents models to address the question of the optimal path of fiscal consolidation given the outlook for natural resource wealth, macroeconomic conditions, and country authority preferences.

KEY ISSUES Context. The region continued to experience strong growth in 2014, led by the continued economic expansion in Cote d’Ivoire. The outlook is for further strong growth, subject to a range of downward risks, in particular political instability ahead of upcoming elections in several countries, and security issues in Mali and Niger. With an elevated fiscal deficit exerting pressure on the balance of payments and the regional financial market, delays in fiscal consolidation or structural reforms pose the main medium-term risks. Policy recommendations: • Fiscal consolidation. Safeguarding external stability in the region will require governments to adhere to their budget deficit reduction plans while maintaining public investment efforts, which will require increasing tax revenue and controlling current expenditure. • Monetary policy. Macroeconomic conditions do not warrant a tightening of monetary policy at this juncture. However, if fiscal deficits do not decline as envisaged, the BCEAO should consider increasing its policy rates. In the mean time, the BCEAO should very closely follow the evolution of the macro-prudential risks flowing from its sharp increase in commercial bank refinancing. • Financial stability. The WAEMU authorities should enforce existing prudential rules and raise standards to international best practice. Ongoing reforms go in the right direction but need to be accelerated. • Structural transformation and regional integration. Policies to promote structural transformation should focus on addressing weaknesses, such as the lack of education and training, finance, and supportive regulatory environments. Countries should refrain from using the possibility to deviate from the common external tariff of the Economic Community of West African States (ECOWAS) in force since January 1, 2015, in order to protect the gains from regional integration in WAEMU.

Presenting innovative modelling approaches to the analysis of fiscal policy and government debt, this book moves beyond previous models that have relied upon the assumption that various age-specific rates and policy variables remain unchanged when it comes to generating government expenditures and tax revenues. As a result of population ageing, current policy settings in many countries are projected to lead to unsustainable levels of public debt; Tax Policy and Uncertainty explores models that allow for feedbacks and uncertainty to combat this.