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.     

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.     

Uncertainty,story-telling and transformative learning: An instructor’s experience of TEFI’s Walking Workshop in Nepal

ABSTRACT

This article recounts three stories from TEFI’s walking workshop in Nepal: the construction of a road through what was once a trekking path; a dance-floor encounter at a Himalayan party; and the arrival of one participant, fatigued by jet lag and disoriented by the new surroundings. These stories of confusion, discomfort and fear are linked by one common theme: the potential of uncertainty to foster deep reflection and nuanced conclusions. The premise that uncertainty is to be valued and even cultivated has been explored in educational theory, spiritual traditions, and research on transformative learning. These sources affirm the role of uncertainty in the process of knowledge creation. However, accepting this role can be challenging for educators because it requires they assume a new identity, one which they may perceive as being at odds with their status as “teacher” the identity of learner. One way for the educator to address this challenge may be through recounting their own stories of uncertainty. Stories of being immersed in unfamiliar situations that challenge, confuse and even frighten – stories, in other words of being a tourist – can foster reflection on an intellectual, emotional and spiritual level, engaging the “whole” person, and thus initiating the educator/learner’s transformative journey.     

Environmental Taxation and Vertical Cournot Oligopolies: How Eco-industries Matter

This article specifies what an optimal pollution tax should be when dealing with a vertical Cournot oligopoly. Polluting firms sell final goods to consumers and outsource their abatement activities to an environment industry. It is assumed that both markets are imperfectly competitive. Thus, the tax is a single instrument used to regulate three sorts of distortions, one negative externality and two restrictions in production. Consequently, the optimal tax rate is the result of a trade-off that depends on the firms’ market power along the vertical structure. A detailed analysis of Cournot-Nash equilibria in both markets is also performed. In this context, the efficiency of abatement activities plays a key-role. It gives a new understanding to the necessary conditions for the emergence of an eco-industrial sector.      

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.     

An Economic Analysis of Auto Compensation Systems: Choice Experiences From New Jersey and Pennsylvania

Nearly since the first automobile traveled on U.S. soil, questions about how best to compensate people injured by their use have been raised. As early as in 1932, in fact, the tort system of imposing costs on negligent drivers was strongly criticized, and a system of compensation without regard to negligence recommended. Yet despite various efforts to identify and implement improved systems during the past more than 70 years, no clear best compensation mechanism has been found. Current discussions have focused on the “choice” system, under which insureds are allowed to select either a tort system or a no‐fault system of compensation at the time of insurance purchase. New Jersey and Pennsylvania, which implemented very similar choice programs in 1989 and 1990, respectively, offer an opportunity to observe the effects of choice on outcomes such as: use of attorneys, speed of payment, and consistency (equity) of payment. Our results indicate outcomes consistent with expectations in New Jersey (NJ), which switched from no‐fault to choice, but inconsistent with expectations in Pennsylvania (PA), which switched from tort to choice. Furthermore, analysis of tort versus no‐fault selectors postchoice in New Jersey and Pennsylvania does not offer clear evidence of no‐fault's lower administrative costs and speedier, more equitable payment in these jurisdictions.     

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