Με την βοήθεια τεχνικών για συστήματα αλληλεπιδρώντων σωματιδίων, σκιαγραφήθηκαν και αποδείχθηκαν θεωρήματα για μοντέλα γνώμης και πολιτιστικής δυναμικής. Τα χωρικά αυτά στοχαστικά μοντέλα εξετάζονται ως γενικεύσεις με μια παράμετρο εμπιστοσύνης ε του γνωστού μοντέλου ψηφοφόρου. Το κεντρικό ερώτημα είναι ο καθορισμός της ασυμπτωτικής δυναμικής, η οποία ενδέχεται να εμφανίζει μετάβαση φάσης από μια ποιοτική συμπεριφορά σε κάποια άλλη. Τα παραχθέντα θεωρήματα αφορούν: α) στην επέκταση του θεωρήματος ομαδοποίησης του Lanchier (2012) σε αυθαίρετους γράφους απόψεων, και β) στην εφαρμογή της μεθοδολογίας των Bramson και Griffeath (1989) σε δυο συστήματα με ουδέτερες αλληλεπιδράσεις, την ουδέτερη εκδοχή των κυκλικών συστημάτων σωματιδίων και γ) το μοντέλο Axelrod για την διάχυση των πολιτιστικών περιοχών. Στα δυο τελευταία μοντέλα εξετάζονται τα φαινόμενα τόσο της καθήλωσης (η άποψη κάθε δράστη μεταβάλλεται πεπερασμένα συχνά) όσο και του κατακερματισμού (μη ομαδοποίηση) του άπειρου συστήματος. / By the use of techniques from interacting particle systems, heuristics and proof have been produced for opinion and cultural dynamical models. These stochastic spatial models are investigated as generalizations with a confidence parameter ε of the well-known voter model. The main question is the characterization of dynamics in the asymptotic limit of time, which may exhibit phase transition from one qualitative behavior to another. The produced theorems are: a) an extension of the clustering theorem by Lanchier (2012) to arbitrary opinion graphs, and b) the appropriation of the Bramson and Griffeath (1989) methodology for systems with neutral interactions, namely, a neutral version of cyclic particle systems and c) the model of Axelrod for the diffusion of cultural domains. In the last two models, the studied phenomena is the fixation of the infinite system (each agent changes her opinion finitely often) to a fragmented configuration (non-clustering).

This research attempts to examine whether economic, social, political and institutional factors affected local public expenditures (per capita) in Taiwan. The panel data regression analysis, covering the period from 1989 to 2007, used statistics from the 21 prefectures (5 cities and 16 counties) of Taiwan by applying the median voter model and political business cycle (PBC) model. The findings from the empirical data suggest that the explanatory variable of the median income is significant and has a positive sign as predicted by the priori expectation, with the exception of economic development expenditure. The gap between the median income and average income variables has positive signs in the total, social welfare, police and economic development expenditures. The tax share variable and grant variable on all categories of spending are significant, but the positive sign of the tax share variable contrasts a priori expectations. The population variable and population density variable have negative signs in different expenditures, while the social welfare and the education, science, and culture expenditures have positive signs. Comparing the difference before and after the downsizing of the Taiwan Provincial Government, the significance of the latter is higher than the former, and the effects of various variables differ. The results of this research also indicated that the variables of the pre-election year, election year and post-election year demonstrated statistical significance with varying directional tendencies, and that the results are inconsistent with the traditional hypothesis of the election cycle. The incumbent magistrates or mayors, regardless of whether they do or do not intend on re-election, exhibit no significant influence on most expenditures, and thus this does not agree with a priori expectations. The administrative satisfactions of incumbent magistrates or mayors have statistically significant influence on the expenditures and deficits. Generally, the Pan-KMT incumbent magistrates or mayors have more motives to increase the total and capital expenditures and deficits than the Pan-DPP. Interestingly, the KMT party, which held the majority of seats in the county council, has a positive sign and statistically significant influence on the expenditure of grants to townships. The evidence has demonstrated that a unified government or divided government (horizontal type or vertical type) has no significant influence on most of the expenditure forms, although a negative sign on social welfare expenditure is evident in 21 counties and cities. The lagged deficit is significant with a positive sign, which implies that the insufficiency of local accountability and deficits are becoming a long-term problem. When comparing the power of the median voter model and political business cycle model in explaining the local public expenditure, a non-nested test was implemented. No model was found to hold an advantage over another model. In brief, the current research indicates that the factors of the majority voters' demands, elections and parties indeed have different influences on various expenditure forms in Taiwan.

The dynamics on networks and the dynamics of networks are usually entangled with each other in many highly connected systems, where the former means the evolution of state and the latter means the adaptation of structure. In this thesis, we will study the coupled dynamics through analytical and computational approaches, where the adaptive networks are driven by learning of various complexities. Firstly, we investigate information diffusion on networks through an adaptive voter model, where two opinions are competing for the dominance. Two types of dynamics facilitate the agreement between neighbours: one is pairwise imitation and the other is link rewiring. As the rewiring strength increases, the network of voters will transform from consensus to fragmentation. By exploring various strategies for structure adaptation and state evolution, our results suggest that network configuration is highly influenced by range-based rewiring and biased imitation. In particular, some approximation techniques are proposed to capture the dynamics analytically through moment-closure differential equations. Secondly, we study an evolutionary model under the framework of natural selection. In a structured community made up of cooperators and cheaters (or defectors), a new-born player will adopt a strategy and reorganise its neighbourhood based on social inheritance. Starting from a cooperative population, an invading cheater may spread in the population occasionally leading to the collapse of cooperation. Such a collapse unfolds rapidly with the change of external conditions, bearing the traits of a critical transition. In order to detect the risk of invasions, some indicators based on population composition and network structure are proposed to signal the fragility of communities. Through the analyses of consistency and accuracy, our results suggest possible avenues for detecting the loss of cooperation in evolving networks. Lastly, we incorporate distributed learning into adaptive agents coordination, which emerges as a consequence of rational individual behaviours. A generic framework of work-learn-adapt (WLA) is proposed to foster the success of agents organisation. To gain higher organisation performance, the division of labour is achieved by a series of events of state evolution and structure adaptation. Importantly, agents are able to adjust their states and structures through quantitative information obtained from distributed learning. The adaptive networks driven by explicit learning pave the way for a better understanding of intelligent organisations in real world.

Orientador: Marcus Aloizio Martinez de Aguiar / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-26T15:46:41Z (GMT). No. of bitstreams: 1 Moreira_CarolinaArruda_M.pdf: 4382090 bytes, checksum: 433897428b81157ccaeb3d7af604a731 (MD5) Previous issue date: 2015 / Resumo: Nesta dissertação, estudamos um processo dinâmico binário similar ao modelo do eleitor em redes complexas. Este modelo descreve uma eleição com dois candidatos e um grupo de N eleitores indecisos, que podem mudar de ideia adotando a opinião de um de seus contatos em uma rede de amigos ou de formadores de opinião. Os nós da rede social possuem estado interno rotulados por 0 ou 1, de acordo com a atual intenção de voto de cada indivíduo. Os formadores de opinião têm ideia fixa e podem influenciar a rede inteira dos eleitores indecisos. Estes são modelados por nós "fixos" na rede, conectados a todos os nós livres da rede de eleitores, aos quais quantificamos por N0 fixos no estado 0 e N1 fixos no estado 1. Calculamos a distribuição de probabilidade P(m) de que o candidato 1 conquiste m votos. Estudamos a dinâmica em redes estrela e comparamos os resultados com os obtidos para redes totalmente conectadas. Em ambos os casos a transição de fase entre os estados de equilíbrio ordenado e desordenado é observada à medida que N0 e N1 se aproximam de zero; no entanto, esse comportamento difere consideravelmente para as duas topologias: enquanto o ponto crítico ocorre exatamente para N0 = N1 = 1para qualquer tamanho N na rede totalmente conectada, tornando a distribuição de equilíbrio uniforme, nas redes estrela o ponto crítico depende de N e se escala com N0 = N1 ? ?N, levando a distribuição de equilíbrio se separar em dois picos, o que reflete os dois estados possíveis do nó central. Obtemos também soluções analíticas aproximadas que se mantêm perto da transição de fase e esclarecem o papel do nó central no processo. Além disso, estendemos a dinâmica abordada para o caso em que cada nó é representado por dois "bits", de modo a existirem quatro estados internos possíveis, (0,0), (0,1), (1,0) e (1,1). Esta abordagem objetiva buscar quais as características dinâmicas de um sistema que apresente nós com restrições na interação. Nesta situação, não encontramos novidades entre as dinâmicas de um e dois bits / Abstract: In this work, we study a dynamical process similar to the voter model on complex networks. This model describes an election with two candidates and a group of N undecided voters that can change their minds by adopting either the opinion of a contact in a social network or the opinion of opinion makers. The nodes of the social network have an internal state labeled by 0 or 1 according to the current voting intention of each individual. The opinion makers have a fixed opinion and can influence the entire set of undecided voters. They are modeled as ''fixed'' nodes connected to all free nodes on the social network and we quantify by N0 the number of nodes fixed in state 0 and by N1 those fixed in state 1. We calculate the probability distribution P(m) that candidate 1 receives m votes. We study this dynamics on star networks and we compare the results with those obtained from fully connected networks. In both cases the transition between the ordered and disordered equilibrium states is observed as N0 and N1 approach zero; however, this behavior differs significantly between the two topologies: while the critical point occurs exactly in N0 = N1 = 1 for fully connected networks and it is independent of the network size N, which leads to a uniform probability distribution, for star networks the critical point depends on N and scales as N0 = N1 ? ?N, and the distribution probability splits into two peaks, reflecting the two possible states of the central node. We also obtain an approximate analytical solution that holds near the phase transition, which clarifies the role of the central node in the process. Besides, we extend the dynamics approach to the case where each node is represented by two ''bits'' such that there are four possible internal states (0,0), (0,1), (1,0) and (1,1). This approach aims to search what are the systems' dynamical characteristics under restrictions in the interaction. In this case, we didn't find any new results between the one and two bits dynamics / Mestrado / Física / Mestra em Física

Dynamical properties of non-equilibrium systems, similar to equilibrium ones, have been shown to obey robust time scaling laws which have enriched the concept of physical universality classes. In the first part of this Dissertation, we present the results of our investigations of some of the critical dynamical properties of systems belonging to the Voter or the Directed Percolation (DP) universality class. To be more precise, we focus on the aging properties of two-state and three-state Potts models with absorbing states and we determine temporal scaling of autocorrelation and autoresponse functions. We propose a novel microscopic model which exhibits non-equilibrium critical points belonging to the Voter, DP and Ising Universality classes. We argue that our model has properties similar to the Generalized Voter Model (GVM) in its Langevin description. Finally, we study the time evolution of the width of interfaces separating different absorbing states. The second part of this Dissertation is devoted to the applications of Machine Learning models in physical systems. First, we show that a trained Convolutional Neural Network (CNN) using configurations from the Ising model with conserved magnetization is able to find the location of the critical point. Second, using as our training dataset configurations of Ising models with conserved or non-conserved magnetization obtained in importance sampling Monte Carlo simulations, we investigate the physical properties of configurations generated by the Restricted Boltzmann Machine (RBM) model. The first part of this research was sponsored by the US Army Research Office and was accomplished under Grant Number W911NF-17-1-0156. The second part of this work was supported by the United States National Science Foundation through grant DMR-1606814. / Doctor of Philosophy / Physical systems with equilibrium states contain common properties with which they are categorized in different universality classes. Similar to these equilibrium systems, non-equilibrium systems may obey robust scaling laws and lie in different dynamic universality classes. In the first part of this Dissertation, we investigate the dynamical properties of two important dynamic universality classes, the Directed Percolation universality class and the Generalized Voter universality class. These two universality classes include models with absorbing states. A good example of an absorbing state is found in the contact process for epidemic spreading when all individuals are infected. We also propose a microscopic model with tunable parameters which exhibits phase transitions belonging to the Voter, Directed Percolation and Ising universality classes. To identify these universality classes, we measure specific dynamic and static quantities, such as interface density at different values of the tunable parameters and show that the physical properties of these quantities are identical to what is expected for the different universal classes. The second part of this Dissertation is devoted to the application of Machine Learning models in physical systems. Considering physical system configurations as input dataset for our machine learning pipeline, we extract properties of the input data through our machine learning models. As a supervised learning model, we use a deep neural network model and train it using configurations from the Ising model with conserved dynamics. Finally, we address the question whether generative models in machine learning (models that output objects that are similar to inputs) are able to produce new configurations with properties similar to those obtained from given physical models. To this end we train a well known generative model, the Restricted Boltzmann Machine (RBM), on Ising configurations with either conserved or non-conserved magnetization at different temperatures and study the properties of configurations generated by RBM. The first part of this research was sponsored by the US Army Research Office and was accomplished under Grant Number W911NF-17-1-0156. The second part of this work was supported by the United States National Science Foundation through grant DMR-1606814.

Orientador: Marcus Aloizio Martinez de Aguiar / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-08-10T18:23:05Z (GMT). No. of bitstreams: 1 Chinellato_DavidDobrigkeit_M.pdf: 15300810 bytes, checksum: 36fdea424f1c7f83a5f50742e82465f8 (MD5) Previous issue date: 2007 / Resumo: Nesta tese, estudamos as propriedades estatísticas de processos dinâmicos de influência em redes complexas sujeitas a perturbações externas. Consideramos redes cujos nós admitem dois estados internos, digamos 0 e 1. Os estados internos se alteram de acordo com os estados dos nós vizinhos. Supomos que há N1 nós com estado interno fixo em 1, N0 elementos com estado interno fixo em 0 e outros N elementos com estado interno livre. Os nós com estado interno ½xo podem ser interpretados como perturbações externas à subrede de N elementos livres. Este sistema é uma generalização do modelo do eleitor [25] e pode descrever diversas situações interessantes, indo de sistemas sociais [26] para a física e a genética. Neste trabalho, calcularemos analiticamente a evolução de um sistema de rede totalmente conectada, obtendo expressões para as distribuições de equilíbrio de uma rede qualquer e também de todas as probabilidades de transição. Em seguida, generalizamos os resultados para o caso em que N0 e N1 são menores do que 1, representando um acoplamento fraco do sistema com um reservatório externo. Mostramos que os resultados exatos são excelentes aproximações para várias outras redes, incluindo redes aleatórias, reticuladas, livres de escala, estrela e mundo pequeno, e estudamos a dinâmica destas outras redes numericamente. Finalmente, demonstramos que, se os dois parâmetros da solução para redes totalmente conectadas, N0 e N1, forem alterados para valores efetivos para cada tipo de rede específico, o nosso resultado analítico explica satisfatoriamente todas as dinâmicas e estados assintóticos de outras topologias. O nosso modelo é portanto bastante geral, se aplicado cuidadosamente / Abstract: We study the statistical properties of in²uence networks subjected to external perturbations. We consider networks whose nodes have internal states that can assume the values 0 or 1. The internal states can change depending on the state of the neighboring nodes. We let N1 nodes be frozen in the state 1, N0 be frozen in the state 0 and the remaining N nodes be free to change their internal state. The frozen nodes are interpreted as external perturbations to the sub-network of N free nodes. The system is a generalization of the voter model [25] and can describe a variety of interesting situations, from social systems [26] to physics and genetics. In this thesis, we calculate analytically the equilibrium distribution and the transition probabilities between any two states for arbitrary values of N, N1 and N0 for the case of fully connected networks. Next we generalize the results for the case where N0 and N1 are smaller than 1, representing the weak coupling of the network to an external reservoir. We show that our exact results are excellent approximations for several other topologies, including random, regular lattices, scale-free, star and small world networks, and study the dynamics of these other networks numerically. We then proceed to show that, by appropriately tuning the two parameters from the solution from fully connected networks, N0and N1, to eÿective values when dealing with other, more sophisticated network types, we can easily explain their asymptotic network behaviour. Our model is therefore quite general in applicability, if used consciously / Mestrado / Física Estatistica e Termodinamica / Mestre em Física

Submitted by Rafael Terra (rflterra@yahoo.com.br) on 2012-05-07T03:21:38Z No. of bitstreams: 1 Dissertation Final Rafael Terra de Menezes May 2012.pdf: 9750545 bytes, checksum: aa5ad52c395ae0a69a42c64b246ce7bf (MD5) / Approved for entry into archive by Gisele Isaura Hannickel (gisele.hannickel@fgv.br) on 2012-05-07T13:37:27Z (GMT) No. of bitstreams: 1 Dissertation Final Rafael Terra de Menezes May 2012.pdf: 9750545 bytes, checksum: aa5ad52c395ae0a69a42c64b246ce7bf (MD5) / Made available in DSpace on 2012-05-07T14:06:46Z (GMT). No. of bitstreams: 1 Dissertation Final Rafael Terra de Menezes May 2012.pdf: 9750545 bytes, checksum: aa5ad52c395ae0a69a42c64b246ce7bf (MD5) Previous issue date: 2012-05-03 / Local provision of public services has the positive effect of increasing the efficiency because each locality has its idiosyncrasies that determine a particular demand for public services. This dissertation addresses different aspects of the local demand for public goods and services and their relationship with political incentives. The text is divided in three essays. The first essay aims to test the existence of yardstick competition in education spending using panel data from Brazilian municipalities. The essay estimates two-regime spatial Durbin models with time and spatial fixed effects using maximum likelihood, where the regimes represent different electoral and educational accountability institutional settings. First, it is investigated whether the lame duck incumbents tend to engage in less strategic interaction as a result of the impossibility of reelection, which lowers the incentives for them to signal their type (good or bad) to the voters by mimicking their neighbors’ expenditures. Additionally, it is evaluated whether the lack of electorate support faced by the minority governments causes the incumbents to mimic the neighbors’ spending to a greater extent to increase their odds of reelection. Next, the essay estimates the effects of the institutional change introduced by the disclosure on April 2007 of the Basic Education Development Index (known as IDEB) and its goals on the strategic interaction at the municipality level. This institutional change potentially increased the incentives for incumbents to follow the national best practices in an attempt to signal their type to voters, thus reducing the importance of local information spillover. The same model is also tested using school inputs that are believed to improve students’ performance in place of education spending. The results show evidence for yardstick competition in education spending. Spatial auto-correlation is lower among the lame ducks and higher among the incumbents with minority support (a smaller vote margin). In addition, the institutional change introduced by the IDEB reduced the spatial interaction in education spending and input-setting, thus diminishing the importance of local information spillover. The second essay investigates the role played by the geographic distance between the poor and non-poor in the local demand for income redistribution. In particular, the study provides an empirical test of the geographically limited altruism model proposed in Pauly (1973), incorporating the possibility of participation costs associated with the provision of transfers (Van de Wale, 1998). First, the discussion is motivated by allowing for an “iceberg cost” of participation in the programs for the poor individuals in Pauly’s original model. Next, using data from the 2000 Brazilian Census and a panel of municipalities based on the viii National Household Sample Survey (PNAD) from 2001 to 2007, all the distance-related explanatory variables indicate that an increased proximity between poor and non-poor is associated with better targeting of the programs (demand for redistribution). For instance, a 1- hour increase in the time spent commuting by the poor reduces the targeting by 3.158 percentage points. This result is similar to that of Ashworth, Heyndels and Smolders (2002) but is definitely not due to the program leakages. To empirically disentangle participation costs and spatially restricted altruism effects, an additional test is conducted using unique panel data based on the 2004 and 2006 PNAD, which assess the number of benefits and the average benefit value received by beneficiaries. The estimates suggest that both cost and altruism play important roles in targeting determination in Brazil, and thus, in the determination of the demand for redistribution. Lastly, the results indicate that ‘size matters’; i.e., the budget for redistribution has a positive impact on targeting. The third essay aims to empirically test the validity of the median voter model for the Brazilian case. Information on municipalities are obtained from the Population Census and the Brazilian Supreme Electoral Court for the year 2000. First, the median voter demand for local public services is estimated. The bundles of services offered by reelection candidates are identified as the expenditures realized during incumbents’ first term in office. The assumption of perfect information of candidates concerning the median demand is relaxed and a weaker hypothesis, of rational expectation, is imposed. Thus, incumbents make mistakes about the median demand that are referred to as misperception errors. Thus, at a given point in time, incumbents can provide a bundle (given by the amount of expenditures per capita) that differs from median voter’s demand for public services by a multiplicative error term, which is included in the residuals of the demand equation. Next, it is estimated the impact of the module of this misperception error on the electoral performance of incumbents using a selection models. The result suggests that the median voter model is valid for the case of Brazilian municipalities. / A provisão local de serviços públicos tem o efeito positivo de aumentar a eficiência, pois cada localidade tem as suas idiossincrasias que determinam uma demanda distinta por serviços públicos. Esta dissertação aborda diferentes aspectos da demanda local por bens e serviços públicos e sua relação com incentivos políticos O texto está dividido em três ensaios. O primeiro ensaio visa testar a existência de yardstick competition nos gastos em educação utilizando um painel de municípios brasileiros. O ensaio estima modelos espaciais de Durbin com dois regimes e efeitos fixos espaciais e temporais por meio de máxima verossimilhança, onde os regimes representam diferentes cenários institucionais de accountability eleitoral e educacional. Primeiro, é investigado se os prefeitos de segundo mandato tendem a interagir menos com os vizinhos como resultado da impossibilidade de reeleição, que reduz os incentivos para sinalizarem seus tipos (bons ou ruins) para os eleitores por meio da reprodução dos gastos de seus vizinhos. Além disso, é avaliado se prefeitos sem apoio político da maioria da câmara dos vereadores (que pode indicar uma falta de apoio dos eleitores) buscam reproduzir os gastos dos vizinhos em maior medida, a fim de aumentarem suas chances de reeleição. Em seguida, o ensaio calcula os efeitos da mudança institucional introduzida pela divulgação do Índice de Desenvolvimento da Educação Básica (IDEB) e de suas metas em abril de 2007 sobre a interação estratégica entre governos locais. Esta mudança institucional possivelmente aumentou os incentivos para os prefeitos seguirem as melhores práticas nacionais, na tentativa de sinalizarem aos eleitores que são competentes, reduzindo assim a importância de transbordamentos de informação local. O mesmo modelo é também testado usando insumos escolares que se acreditam aumentarem o desempenho dos alunos no lugar de gastos com educação. Os resultados mostram evidências de yardstick competition nos gastos em educação. A autocorrelação espacial é menor entre os prefeitos em segundo mandato e maior entre os prefeitos com o apoio da minoria (i.e., com uma margem menor de votos). Além disso, a mudança institucional introduzida pelo IDEB reduziu a interação espacial nos gastos educação e na definição dos insumos escolares, diminuindo assim a importância de transbordamentos de informação local. O segundo ensaio investiga o papel desempenhado pela distância geográfica entre os pobres e não pobres na determinação da demanda local por redistribuição de renda. Em particular, o estudo fornece um teste empírico do modelo de altruísmo delimitado geograficamente proposto em Pauly (1973), incorporando ainda a possibilidade de custos de x participação associados à provisão de transferências (Van de Wale, 1998). Primeiramente, a discussão é motivada permitindo que o modelo original Pauly incorpore um "custo iceberg" de participação nos programas para as pessoas pobres. Foram utilizados dados seccionais do Censo Demográfico de 2000 e um painel de municípios com base na Pesquisa Nacional por Amostra de Domicílios (PNAD) de 2001 a 2007. Todas as variáveis explicativas que constituem medidas de distância indicam que uma maior proximidade entre pobres e não pobres está associada a uma melhor cobertura dos programas (demanda por redistribuição). Por exemplo, um aumento de 1 hora no tempo gasto em deslocamento casa-trabalho pelos pobres reduz a cobertura em 3,158 pontos percentuais. Este resultado é semelhante ao de Ashworth, Heyndels e Smolders (2002), mas definitivamente não se deve à existência de vazamentos nos programas. Para diferenciar empiricamente os efeitos resultantes de custos de participação daqueles devido ao altruísmo geograficamente delimitado, um teste adicional é realizado com dados em painel obtidos junto as PNAD de 2004 e de 2006, que avaliam o número de benefícios e o valor do benefício médio recebido pelos beneficiários. As estimativas sugerem que tanto o custo quanto o altruísmo desempenham papéis importantes na determinação da cobertura/focalização de programas sociais no Brasil e, portanto, na determinação da demanda por transferências. Os resultados indicam também que o tamanho do orçamento para a redistribuição tem um impacto positivo na cobertura dos programas. O terceiro ensaio tem como objetivo testar empiricamente a validade do modelo do eleitor mediano para o caso brasileiro. As informações municipais são provenientes do Censo Demográfico e do Tribunal Supremo Eleitoral para o ano de 2000. Primeiramente, a demanda do eleitor mediano para os serviços públicos locais é estimada. As cestas ofertadas pelos candidatos à reeleição são identificadas como os gastos realizados durante o primeiro mandato. A suposição de informação perfeita dos candidatos sobre a demanda mediana é relaxada e uma hipótese mais fraca, de expectativas racionais, é imposta. Assim, os representantes podem se enganar quanto à demanda mediana ao que se denominou “erros de percepção”. Assim, em um determinado ponto no tempo, os representantes podem fornecer uma cesta (dada pelas despesas per capita), que difere por um termo de erro multiplicativo da demanda do eleitor mediano por serviços públicos, o qual está incluído nos resíduos da equação de demanda. Em seguida, calcula-se o impacto do módulo deste “erro de percepção” sobre o desempenho eleitoral dos prefeitos utilizando modelos de seleção. O resultado sugere que o modelo do eleitor mediano é válido para o caso dos municípios brasileiros.

Collective decision making can be seen as a means of designing and understanding swarm robotics systems. While decision-making is generally conceived as the cognitive ability of individual agents to select a belief based only on their preferences and available information, collective decision making is a decentralized cognitive process, whereby an ensemble of agents gathers, shares, and processes information as a single organism and makes a choice that is not attributable to any of its individuals. A principled selection of the rules governing this cognitive process allows the designer to define, shape, and foresee the dynamics of the swarm.We begin this monograph by introducing the reader to the topic of collective decision making. We focus on artificial systems for discrete consensus achievement and review the literature of swarm robotics. In this endeavor, we formalize the best-of-n problem—a generalization of the logic underlying several cognitive problems—and define a taxonomy of its possible variants that are of interest for the design of robot swarms. By leveraging on this understanding, we identify the building-blocks that are essential to achieve a collective decision addressing the best-of-n problem: option exploration, opinion dissemination, modulation of positive feedback, and individual decision-making mechanism. We show how a modular perspective of a collective decision-making strategy allows for the systematic modeling of the resulting swarm performance. In doing so, we put forward a modular and model-driven design methodology that allows the designer to study the dynamics of a swarm at different level of abstractions. Successively, we employ the proposed design methodology to derive and to study different collective decision-making strategies for the best-of-n problem. We show how the designed strategies can be readily applied to different real-world scenarios by performing two series of robot experiments. In the first series, we use a swarm of 100 robots to tackle a site-selection scenario; in the second series, we show instead how the same strategies apply to a collective perception scenario. We conclude with a discussion of our research contributions and provide futuredirection of research. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished

The aim of this graduate thesis is proposing an optimization of the likely voter model parameter values utilized by Median (research agency) based on secondary analysis of data from the third wave and post-election follow-up of the Czech Household Panel Study 2017 and the Median omnibus survey. The theoretical chapter presents selected aspects of the analyzed likely voter model parameters. Secondary data analysis confirms hypotheses regarding the relationships of: 1) voter turnout, prior voting behavior and the intent to vote, 2) pre-election voting preferences and actual voting behavior, 3) reported prior voting behavior and time elapsed since the prior election. Hypotheses are confirmed, and analysis results are utilized in construction of an optimized likely voter model. This model's results are then compared to the results of four currently or formerly published likely voter models (MEDIAN, CVVM2017, CVVM2018, KANTAR), all computed using an identical dataset (September/October 2017 Median omnibus survey). Based on prior-set comparison criteria, the proposed model has the highest ranking out of all the compared models. Areas of future research proposed, namely exploring the relationship between prior voting behavior misreporting and voting preference trends, in accordance with cognitive...

Essay 1 (with Mikael Elinder): We show that house prices in general did not respond to a large cut in the property tax in Sweden. Our estimates are based on rich register data covering more than 100,000 sales over a time period of two and a half years. Because the Swedish property tax is national and thus unrelated to local public goods, our setting is ideal for causal identification of the property tax on house prices. Our result that house prices did not respond to the tax cut at the time of implementation cannot be explained by early capitalization at the time of announcement. Two other stories appear to explain our results. First, it is possible that house buyers expect an offsetting increase in the supply of housing. Second, house buyers might simply not understand how the tax cut affects total future costs of owning a house. Unfortunately, it has proven difficult to disentangle the two mechanisms, and we must therefore conclude that both may be relevant. Essay 2:  I investigate government consumption smoothing (sensitivity) under a balanced budget rule in Swedish municipalities. In general, I find Swedish municipalities to be highly consumption sensitive. Municipalities consume 87.6% out of predicted current revenues in the time period leading up to the implementation of the balanced budget rule, and they consume 76.3% out of predicted current revenue in thetime period following the implementation. Fiscally weak municipalities are found to be more consumption sensitive than fiscally strong municipalities. Very weak municipalities have become more consumption sensitive compared with very strong municipalities since the implementation of the balanced budget rule. Thus, I find indicative evidence that both credit market constraints and formal budget rules such as balanced budget rules increase municipal consumption sensitivity Essay 3: Using the Swedish municipal sector as my political laboratory, I study the effect of a coalition partner on policy outcomes. I use a version of Regression-Discontinuity Design (RDD) specifically suited to proportional systems to define close elections, which can be used for identifying the effect of the Left Party as coalition partner to the Social Democrats. The Left Party is found to have a positive and medium sized effect on the municipal income tax rate. The positive effect is in line with what we expect given the policy preferences of Left Party representatives, but also given the predictions from political fragmentation theory. I find no effects on expenditures or debt, and the negative result for investments is not robust. Essay 4 (with Linuz Aggeborn): In a model where voters and politicians have different preferences for how much to spend on basic welfare services contra immigration, we conclude that established politicians that are challenged by right-wing populists will implement a policy with no spending on immigration if the cost of immigration is high enough. Additionally, adjustment to right-wing populist policy is more likely when the economy is in a recession. Voters differ in their level of private consumption in such a way that lower private consumption implies higher demand for basic welfare services at the expense of immigration, and thus stronger disposition to support right-wing populist policies. We propose that this within-budget-distributional conflict can arise as an electorally decisive conflict dimension if parties have converged to the median voter on the size-of-government issue. / <p>Felaktigt isbn: 978-91-85519-61-3</p>