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.     

Patterns of Investor-State Dispute Settlement Decisions

This paper examines the pattern of settlements, investor wins and state wins in investor-state dispute settlement cases, focusing on the impact of arbitration rules, the resources and experience of the litigants, the type of treaty breach under investigation, and the pattern of state intervention. Logistic regression results show that settlements are more likely when investors do not disclose their allegations publicly, when the host state has been involved in a greater number of past cases, and when the respondent state has a higher control-of-corruption rating. Panel awards to investors are more likely in cases of alleged direct expropriation and less likely for indirect expropriation. Panel decisions favoring the state increase with higher per capita income and rule-of-law ratings.     

Liking what others “Like”: using Facebook to identify determinants of conformity

In this paper we explore the micro-level determinants of conformity. Members of the social networking service Facebook express positive support to content on the website by clicking a Like button. We set up a natural field experiment to test whether users are more prone to support content if someone else has done so before. To find out to what extent conformity depends on group size and social ties we use three different treatment conditions: (1) one stranger has Liked the content, (2) three strangers have Liked the content, and (3) a friend has Liked the content. The results show that one Like from a single stranger had no impact. However, increasing the size of the influencing group doubled the probability that subjects expressed positive support. Friendship ties were also decisive. People were, on average, four times more likely to press the Like button if a friend, rather than a stranger, had done so before them. The existence of threshold effects in our experiment clearly shows that both group size and social proximity matters when opinions are shaped.     

Cuba,Trade Dependency and the GATT/WTO System

Cuba sought economic independence from the U.S. and its reliance on sugar exports after its 1959 revolution, but subsequently developed new dependency relationships. In the meantime, Cuba remained inside the General Agreement on Tariffs and Trade (GATT), despite conducting most of its trade outside it. This paper explores the political economy of Cuba’s participation in the GATT and later the World Trade Organization (WTO). Documents show that Cuba sought to use its participation to gain new markets and influence in the developing world. While Cuba has gained little economically from its participation, in recent years it has diversified its exports and trade partners, and its trade interests now align more closely with WTO rules. Economic reforms will be necessary in order for Cuba to benefit.     

Competition and cooperation in the exploitation of the groundwater resource

We study the exploitation of a common groundwater resource, first as a static and then as a differential game, in order to take into account the strategic and dynamic interactions among the users of the resource. We suppose that firms can form coalitions or can decide not to cooperate. The non-cooperation regime is characterized by pumping that lead to depletion of the aquifer; the cooperation preserves the resource. Open-loop and feedback equilibria have been computed and compared in order to characterize the existence of cooperators and defectors in water resources management.     

Analyse der Marktaussichten von Biogasanlagen

Without guaranteed compensation, granted by the German Renewable Energy Sources Act (Erneuerbare Energien Gesetz/EEG), biogas plants compete with all other plant types on the market for electrical energy. However, exchange-based electricity products do not currently permit an economically viable operation of biogas plants owing to their cost situation.