Expectations or Guarantees? I Want It All! A crossroad between games and MDPs

When reasoning about the strategic capabilities of an agent, it is important to consider the nature of its adversaries. In the particular context of controller synthesis for quantitative specifications, the usual problem is to devise a strategy for a reactive system which yields some desired performance, taking into account the possible impact of the environment of the system. There are at least two ways to look at this environment. In the classical analysis of two-player quantitative games, the environment is purely antagonistic and the problem is to provide strict performance guarantees. In Markov decision processes, the environment is seen as purely stochastic: the aim is then to optimize the expected payoff, with no guarantee on individual outcomes. In this expository work, we report on recent results introducing the beyond worst-case synthesis problem, which is to construct strategies that guarantee some quantitative requirement in the worst-case while providing an higher expected value against a particular stochastic model of the environment given as input. This problem is relevant to produce system controllers that provide nice expected performance in the everyday situation while ensuring a strict (but relaxed) performance threshold even in the event of very bad (while unlikely) circumstances. It has been studied for both the mean-payoff and the shortest path quantitative measures.Comment: In Proceedings SR 2014, arXiv:1404.041

Strategy Synthesis for Multi-dimensional Quantitative Objectives

Multi-dimensional mean-payoff and energy games provide the mathematical foundation for the quantitative study of reactive systems, and play a central role in the emerging quantitative theory of verification and synthesis. In this work, we study the strategy synthesis problem for games with such multi-dimensional objectives along with a parity condition, a canonical way to express $\omega$-regular conditions. While in general, the winning strategies in such games may require infinite memory, for synthesis the most relevant problem is the construction of a finite-memory winning strategy (if one exists). Our main contributions are as follows. First, we show a tight exponential bound (matching upper and lower bounds) on the memory required for finite-memory winning strategies in both multi-dimensional mean-payoff and energy games along with parity objectives. This significantly improves the triple exponential upper bound for multi energy games (without parity) that could be derived from results in literature for games on VASS (vector addition systems with states). Second, we present an optimal symbolic and incremental algorithm to compute a finite-memory winning strategy (if one exists) in such games. Finally, we give a complete characterization of when finite memory of strategies can be traded off for randomness. In particular, we show that for one-dimension mean-payoff parity games, randomized memoryless strategies are as powerful as their pure finite-memory counterparts.Comment: Conference version published in CONCUR 2012, LNCS 7454. Journal version published in Acta Informatica, volume 51, issue 3-4, Springer, 201

On the representativeness of political corpora in linguistic research

There is a long tradition of linguistic research on political discourse from various theoretical perspectives, including critical discourse analysis (see among many others Fairclough 1995, Fairclough & Fairclough 2012, Wodak 1989), lexicometric approaches (see for instance Arnold 2005, Mayaffre 2005, 2016, Mayaffre & Poudat 2013, Authors 2015a) or cognitive linguistic approaches to metaphor (see among many other Charteris Black 2011, Musolff 2004, 2013, 2016 L’Hôte 2012). In these studies, political corpora collected from discourses by political elites (presidential debates, presidential addresses, public speeches,…) often appear to be overrepresented, leaving aside other forms of political discourses such as media discourse on political issues (see however Musolff 2004, 2013) or citizen discourse. As Bougher (2012 :149) posits for metaphor analysis : “while research on metaphors in political discourse has flourished in recent years, the focus on elite communication has left metaphor’s wider capacity as a reasoning tool for citizens underexplored”. This results in a certain lack of representativeness of the political domain in linguistic studies. Indeed, political discourse is not restricted to the political elites alone. Advocating a more global to political corpora, including corpora from different subdomains of the political spectrum, our talk is structured in two main parts. Firstly, we will propose a quantitative bibliographic analysis aiming at assessing what type of political corpora are frequently used in linguistic research. Secondly, on the basis of previous and current analyses of different kinds of political corpora (including citizen, media and elite discourse) we have been collecting in the framework of the ADAPOF-project (see for example Authors 2015b), we will illustrate how taking this variety of political genres into account, allows us to unravel phenomena such as conceptual alignment or metaphor circulation, related to specific political issues (in this case Belgian federalism). References Arnold, E. (2005). Le discours de Tony Blair (1997-2004). Corpus 4 | URL : http://corpus.revues.org/340. Authors (2015a). Constructing Quebec and Wallonia How political parties speak about their region. In Authors (ed), Minority Nations in Multinational Federations : A comparative study of Quebec and Wallonia, London & New-York : Rouledge, pp. 49-81. Authors (2015). Folle machine ou solide relation « living apart together » ? Le rôle des métaphores dans la perception citoyenne du fédéralisme belge. Mots. Les Langages du Politique, 109 | URL : http://journals.openedition.org/mots/22156. Bougher, L. (2012). The case for metaphor in political reasoning and cognition. Political Psychology, 33 (1), 145-163. Charteris-Black, J. (2011). Politicians and Rhetoric. The Persuasive Power of Metaphor, Houndmills : Palgrave Macmillan. Fairclough, N. (1995). Critical Discourse Analysis : the Critical Study of Language. New-York : Longman Group. Fairclough, I. & Fairclough, N. (2012). Political Discourse Analysis. A Method for Advanced Students. London & New-York : Routledge. L’Hôte, E. (2012). “Breaking up Britain”? Métaphores et discours sur la dévolution au Royaume-Uni. In Authors (eds.) Les relations communautaires en Belgique, Approches politiques et linguistiques, , Louvain-la-Neuve, Academia- L’Harmattan (Science politique), p. 161-189. Mayaffre, D. (2005). Les corpus politiques : objet, méthode et contenu. Introduction », Corpus, 4 | URL : http:// corpus.revues.org/292. Mayaffre, D. (2016). Du candidat au président : Panorama logométrique de François Hollande. Mots. Les Langages du Politique, 112 | URL : http://journals.openedition.org/mots/22479. Mayaffre, D. & Poudat, C. (2013).Quantitative Approaches to Political Discourse : Corpus Linguistics and Text Statistics. . In K. Fløttum (ed.), Speaking of Europe : Approaches to Complexity in European Political Discourse, Amsterdam & Philadelphia : John Benjamins, pp. 135-150. Musolff, A. (2004). Metaphor and Political Discourse Analogical Reasoning in Debates about Europe. Houndmills : Palgrave MacMillan. Musolff, A. (2013).The heart of Europe : Synchronic Variation and Historical Trajectories of a Political Metaphor. In K. Fløttum (ed.), Speaking of Europe : Approaches to Complexity in European Political Discourse, Amsterdam & Philadelphia : John Benjamins, pp. 135-150 Musolff, A. (2016). Political Metaphor Analysis : Discourse and Scenarios. London & New-York : Bloomsbury. Wodak, R. (ed.)(1989). Language, Power and Ideology : Studies in Political Discourse. Amsterdam & Philadelphia : John Benjamins

Defining and explaining the autonomy of Austrian, Belgian and German executives in the Council of the European Union vis-à-vis their domestic parliaments : an outcome oriented, case specific and qualitative comparative analysis

This doctoral dissertation examines from a comparative perspective, the negotiation autonomy of Austrian Belgian and German federal executives in the Council of the European Union vis-à-vis their domestic parliaments. In particular, it aims at explaining to what extent, how and why regional and national parliamentary actors scrutinise EU decision-making processes, as well as the consequences on the negotiation autonomy of federal executives. This thesis presents original empirical data on four legislative decision-making processes (period 2009-2014) in the environmental policy field, a competence partly regionalised in Austria, Belgium and Germany. The study uses the Qualitative Comparative Analysis (QCA) method and assesses the impact these following five variables have on the negotiation autonomy of federal executives: (1) the preference homogeneity between federal executives and domestic parliaments, (2) the cohesion of the domestic parliamentary system, (3) the existence of an informational asymmetry in favour of federal executives, (4) the domestic salience of the EU decision-making process, and finally, (5) the impact from the implementing powers domestic actors own. Overall, this doctoral dissertation defends two main theoretical (and empirical) arguments. First, the dissertation shows that in federal Member States, the scrutiny of EU affairs conducted by regional parliaments do matter. It is the combined actions of national and regional parliaments (the parliamentary system) that explain the degree of negotiation autonomy for federal executives. Second, the study also demonstrates that a high level of activity from domestic parliaments does not directly translate into diminishing autonomy for the executive. These are crucial findings as most studies focusing on (sub)national parliaments and the European Union (EU) rest on the implicit assumption that strong and active parliaments in EU affairs lead to an improved accountability of the governments. Against this background, the results show that federal executives enjoy an important level of negotiation autonomy vis-à-vis their domestic parliaments. In light of the debate on the re-parliamentarisation of the European Union and on the democratic deficit, this finding has strong outcomes. In fact, if parliaments conduct inefficient scrutiny, then domestic parliaments must go beyond the mere control of their executive in order to be active. In other words, it is not only the quantity of actions that matters, but also the effectiveness of parliamentary scrutiny. On this aspect, the doctoral dissertation highlights the fact that an important amount of the scrutiny conducted by parliaments does not fill the classical functions of parliaments (i.e. informational, control or communicating functions). When dealing with EU affairs, domestic parliaments thus have a function to support their executive in EU negotiations vis-à-vis other Member States and EU institutions. Hence, the input of domestic parliaments in EU governance and decision-making processes must not only be understood as a way to increase the legitimacy of EU decision-making processes, but also as an opportunity for the executive to secure domestic support in EU negotiations. More specifically, the level of autonomy of federal executives is closely bound to the presence or absence of homogenous preferences, and to the salience of EU decision- making processes. On salience, the analysis depicts interesting results. In reality, a high level of salience (combined with homogenous preferences between the Agent and the Principal) is leading to increased negotiation autonomy for the executive. However, the configurational analysis reveals that, combined with a non-cohesive Principal, a lower level of salience leads to less negotiation autonomy. Contrary to what was found in previous studies, domestic salience for an EU proposal will not always lead to higher scrutiny from domestic parliaments. This doctoral dissertation also emphasises that the degree of autonomy of executives in EU affairs is to a large extent country-specific. In fact, Austrian and Belgian executives enjoy a high degree of autonomy in EU negotiations whereas the German executive has less room for manoeuver vis-à-vis its domestic parliaments. As such, this finding confirms previous results from scholars focusing on the institutional strength and degree of activity of domestic parliaments in EU affairs. However, the dissertation goes one step further by highlighting the fact that the formal strength and degree of activity by parliaments is also affecting the room for manoeuver federal executives have in EU negotiations. In turn, the doctoral dissertation invites scholars to open a new research agenda focusing not only on the strength and activity of parliaments, but also on the quality and effectiveness of their actions. Finally, the dissertation offers a first empirical analysis on the relationship between several parliaments (regional and federal) within one Member States. The empirical data shows that the involvement and activity of regional parliaments in Austria, Belgium and Germany on EU affairs is relatively modest, even when EU proposals touch upon shared or regionalised policies. Nonetheless, an interesting finding is the role upper houses have played in these Member States (at the exception of Belgium). Upper houses were the most active parliaments in scrutinizing EU environmental policies in Germany and Austria. In light of the debates on the effect of bicameralism in Western democracies, this paper shows that stronger parliamentary systems - such as the ones in Austria and Germany - tend to seize benefits and opportunities derived from the post-Lisbon era more frequently. In particular, upper houses reinforce their position within the domestic parliament system at the expense of regional parliaments.(POLS - Sciences politiques et sociales) -- UCL, 201