Cointegration and control: Assessing the impact of events using time series data

Control groups can provide counterfactual evidence for assessing the impact of an event or policy change on a target variable. We argue that fitting a multivariate time series model offers potential gains over a direct comparison between the target and a weighted average of controls. More importantly, it highlights the assumptions underlying methods such as difference in differences and synthetic control, suggesting ways to test these assumptions. Gains from simple and transparent time series models are analysed using examples from the literature, including the California smoking law of 1989 and German reunification. We argue that selecting controls using a time series strategy is preferable to existing data‐driven regression methods.     

Are people in the SADC region willing to pay more tax to fund public healthcare?

ABSTRACT

For Africa to develop and achieve sustainable development, African governments have to prioritise spending on public health. However, the current spending data shows that health spending is a continuing struggle for African countries. Many researchers have the view that African governments have to collect more tax to spend enough on public healthcare. The question here is what extent people are willing to pay more tax to increase spending on public healthcare? Employing a multilevel regression model on Afrobarometer survey data, this paper examined to what extent individual and country level factors influence people’s willingness to pay more tax to increase spending on public healthcare in 12 Southern African Development Community (SADC) member states. This study found that peoples’ trust in their government is an important determinant of willingness to pay more tax, while factors such as the country’s quality of democracy, economic condition, and current per capita health expenditure have no influence.     

Brexit: How Will UK Agriculture Fare?

There is little doubt that Brexit would have significant implications for UK agriculture, a sector with strong trade links to the EU and strong reliance on CAP income support. This article reports preliminary results from employing a Computable General Equilibrium Model, a Partial Equilibrium Model and Farm Level Models to explore selected trade and domestic policy scenarios post‐Brexit. These allow for the estimation of changes in producer prices, production and farm incomes against a baseline scenario of continued EU membership. Under a Free Trade Agreement with the EU, agricultural impacts are relatively modest. By contrast, unilateral removal of import tariffs has significant negative impacts on prices, production and incomes. Adoption of the EU's WTO tariff schedule for all imports favours net importers (e.g. dairy) and harms net exporters (e.g. sheep). Given the strong dependence of most UK farms on direct payments, their removal worsens negative impacts of new trade arrangements and offsets positive impacts. Impacts vary across different types and sizes of farm, but also regionally. However, the period of adjustment to new trade and domestic policy conditions may prove very challenging for a large number of farm businesses.     

Price Commitment versus Flexibility: the Role of Exchange Rate Uncertainty and its Implications for Exchange Rate Passthrough

The paper investigates the incentives to commit price or retain price flexibility in a model in which exporting firms face different degrees of exchange rate uncertainty. The result shows that introducing exchange rate uncertainty can lead to the endogenous emergence of a unique leader–follower equilibrium; which firm emerges as price leader depends on the substitutability of products, the magnitude of exchange rate uncertainty, and the cost structure. This study may provide one explanation as to why some exporters set price before the realization of the nominal exchange rates (“sticky price”). The results imply exchange rate variability affects exchange rate passthrough.     

Building Small City and Town Sams and CGE Models

In this paper we attempt to describe both the data sources and organizational methods that allow for effective and easily created SAMs and regional computable general equilibrium (CGE) models. Small cities of around 100,000 people will face very different constraints than a town of 2000 people. Unfortunately, most CGE models typically describe relatively large geographical areas and are therefore not able to capture the uniqueness of individual cities within the region. An illustrative example using these methods demonstrates that the economic impacts vary substantially over different municipalities to the same economic shock.     

Understanding Urban Inequality: A Model Based on Existing Theories and an Empirical Illustration

In the debate on urban inequality, Sassen’s theory on social polarization and Wilson’s theory on spatial mismatch have received much attention. Where Sassen highlights the decline of the middle classes, Wilson focuses on the upgrading of urban labour markets. In this article we argue that both theories may be valid, but that they have to be put in a more extended theoretical framework. Of central importance are national institutional arrangements, membership of different ethnic groups and networks, and place–specific characteristics rooted in local socio–economic histories. As a first empirical illustration of our model, we use data on the labour markets of Amsterdam and Rotterdam and show that different forms of inequality can be found both in economic sectors and within ethnic groups. The model we present could be used both to reinterébatpret existing data and as an analytical framework for the analysis of different forms of urban inequality. Dans le d& sur l’inégalitéurbaine, la théorie de la polarisation sociale de Sassen et celle de la disparité spatiale de Wilson ont retenu l’attention. Alors que Sassen souligne le déclin des classes moyennes, Wilson s’attache à la revalorisation des marchés du travail urbains. Cet article soutient que, si ces deux théories sont admissibles, elles doivent étre placées dans un cadre théorique plus large. En effet, sont essentielles les dispositions institutionnelles nationales, l’adhésion de différents réseaux et groupes ethniques, et les spécificités du lieu enracinées dans les histoires socio–économiques locales. Comme première illustration empirique de notre modèle, nous utilisons des données relatives aux marchés du travail d’Amsterdam et de Rotterdam pour montrer qu’il y existe différentes formes d’inégalitéà la fois dans les secteurs économiques et les groupes ethniques. Le modèle présenté pourrait servir à réinterpréter les données existantes et fournir un cadre à l’analyse des diverses formes d’inégalité urbaine.     

Symmetry and order in the portfolio allocation problem

Summary. This research studies the role of multivariate distribution structures on random asset returns in determining the optimal allocation vector for an expected utility maximizer. All our conclusions pertain for the set of risk averters. By carefully disturbing symmetry in the distribution of the, possibly covarying, returns, we ascertain the ordinal structure of the optimized allocation vector. Rank order of allocations is also established when a permutation symmetric random vector is mapped into the returns vector through location and scale shifts. It is shown that increased dispersion in the vectors of location and scale parameters benefit, ex-ante, investors as does a decrease in the rank correlation coefficient between the location and scale parameter vectors. Revealed preference comparative static results are identified for the location and scale vectors of asset returns. For most issues addressed, we arrive at much stronger inferences when a safe asset is available. Received: August 8, 2000; revised version: January 8, 2001     

Institutional design and the closure of public facilities in transition economies

As part of the reforms of their systems for financing and delivering health care, many transition economies, particularly in central and eastern Europe, have adopted national insurance funds that are institutionally separate from ministries of health. Most of these countries have also grappled with the problem of restructuring the delivery system, especially the need to reduce hospital capacity. Although improving the performance of medical care providers through a shift from passive budgeting to explicitly incentive mechanisms is important, why this change in financial relations between the government and providers could not be implemented simply by reforming the role of health ministries is not obvious. This paper presents an explicit rationale for the separation of powers between the regulator (the ministry of health) and the financing body (the insurance fund), based on the inability of a single agency to commit to closing hospitals. JEL classification: L51, P20, P35, I18.