14 resultados para Econometria

em AMS Tesi di Dottorato - Alm@DL - Università di Bologna


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Gli investimenti diretti esteri (IDE) giocano un ruolo importante nella crescita economica e nello sviluppo territoriale. Con il notevole aumento dei flussi IDE nel settore agroalimentare a livello mondiale l’attenzione si è concentrata sul dibattito relativo alle determinanti che spingono alla scelta di un territorio piuttosto che un altro. Non esiste ancora un lavoro definitivo ed univoco sulle determinanti degli IDE. Alcune delle più frequenti analisi sui fattori che influenzano gli IDE includono: l’entità del mercato, il costo del lavoro, i tassi di interesse, le barriere protezionistiche, tassi di cambio, predisposizione all’export, struttura del mercato, distanze geografiche, stabilità politica e affinità culturale. Questo lavoro si propone di analizzare le determinanti nel settore agroalimentare italiano sia teoricamente che empiricamente. A questo scopo è stata applica come base teorica il paradigma OLI di Dunning e i principi legati agli investimenti orizzontali al settore agroalimentare regionale italiano. Sono state esaminate le determinanti degli investimenti diretti inward in questo settore. Le risultanti suggeriscono una relazione positiva tra la presenza di attività di servizi e la presenza di IDE nelle diverse Regioni. In un Paese ad economia avanzata come l’Italia, strategie territoriali e di impresa basate sui costi e sul mercato non sono caratterizzanti per attrarre multinazionali straniere, mentre la dotazione di servizi e infrastrutture rappresentano un nuovo obiettivo su cui le Regioni devono puntare per aprire i territori alle sfide della globalizzazione. Questa ricerca unisce analisi statistica ed econometria e studio bibliografico per approfondire e comprendere la materia in oggetto e fornire nuovi elementi e spunti su cui discutere.

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In my PhD thesis I propose a Bayesian nonparametric estimation method for structural econometric models where the functional parameter of interest describes the economic agent's behavior. The structural parameter is characterized as the solution of a functional equation, or by using more technical words, as the solution of an inverse problem that can be either ill-posed or well-posed. From a Bayesian point of view, the parameter of interest is a random function and the solution to the inference problem is the posterior distribution of this parameter. A regular version of the posterior distribution in functional spaces is characterized. However, the infinite dimension of the considered spaces causes a problem of non continuity of the solution and then a problem of inconsistency, from a frequentist point of view, of the posterior distribution (i.e. problem of ill-posedness). The contribution of this essay is to propose new methods to deal with this problem of ill-posedness. The first one consists in adopting a Tikhonov regularization scheme in the construction of the posterior distribution so that I end up with a new object that I call regularized posterior distribution and that I guess it is solution of the inverse problem. The second approach consists in specifying a prior distribution on the parameter of interest of the g-prior type. Then, I detect a class of models for which the prior distribution is able to correct for the ill-posedness also in infinite dimensional problems. I study asymptotic properties of these proposed solutions and I prove that, under some regularity condition satisfied by the true value of the parameter of interest, they are consistent in a "frequentist" sense. Once I have set the general theory, I apply my bayesian nonparametric methodology to different estimation problems. First, I apply this estimator to deconvolution and to hazard rate, density and regression estimation. Then, I consider the estimation of an Instrumental Regression that is useful in micro-econometrics when we have to deal with problems of endogeneity. Finally, I develop an application in finance: I get the bayesian estimator for the equilibrium asset pricing functional by using the Euler equation defined in the Lucas'(1978) tree-type models.

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This thesis contains three essays on microeconometrics, networks and economic development. In the first two essays I focus on developing country settings (Tanzania and Nepal respectively) to study how rural villagers form their social networks, and how the existence of these informal links impacts their welfare. The third essay focuses on the international trade of arms to investigate whether the political orientation of government in power makes any difference to arms export policy.

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Life is full of uncertainties. Legal rules should have a clear intention, motivation and purpose in order to diminish daily uncertainties. However, practice shows that their consequences are complex and hard to predict. For instance, tort law has the general objectives of deterring future negligent behavior and compensating the victims of someone else's negligence. Achieving these goals are particularly difficult in medical malpractice cases. To start with, when patients search for medical care they are typically sick in the first place. In case harm materializes during the treatment, it might be very hard to assess if it was due to substandard medical care or to the patient's poor health conditions. Moreover, the practice of medicine has a positive externality on the society, meaning that the design of legal rules is crucial: for instance, it should not result in physicians avoiding practicing their activity just because they are afraid of being sued even when they acted according to the standard level of care. The empirical literature on medical malpractice has been developing substantially in the past two decades, with the American case being the most studied one. Evidence from civil law tradition countries is more difficult to find. The aim of this thesis is to contribute to the empirical literature on medical malpractice, using two civil law countries as a case-study: Spain and Italy. The goal of this thesis is to investigate, in the first place, some of the consequences of having two separate sub-systems (administrative and civil) coexisting within the same legal system, which is common in civil law tradition countries with a public national health system (such as Spain, France and Portugal). When this holds, different procedures might apply depending on the type of hospital where the injury took place (essentially whether it is a public hospital or a private hospital). Therefore, a patient injured in a public hospital should file a claim in administrative courts while a patient suffering an identical medical accident should file a claim in civil courts. A natural question that the reader might pose is why should both administrative and civil courts decide medical malpractice cases? Moreover, can this specialization of courts influence how judges decide medical malpractice cases? In the past few years, there was a general concern with patient safety, which is currently on the agenda of several national governments. Some initiatives have been taken at the international level, with the aim of preventing harm to patients during treatment and care. A negligently injured patient might present a claim against the health care provider with the aim of being compensated for the economic loss and for pain and suffering. In several European countries, health care is mainly provided by a public national health system, which means that if a patient harmed in a public hospital succeeds in a claim against the hospital, public expenditures increase because the State takes part in the litigation process. This poses a problem in a context of increasing national health expenditures and public debt. In Italy, with the aim of increasing patient safety, some regions implemented a monitoring system on medical malpractice claims. However, if properly implemented, this reform shall also allow for a reduction in medical malpractice insurance costs. This thesis is organized as follows. Chapter 1 provides a review of the empirical literature on medical malpractice, where studies on outcomes and merit of claims, costs and defensive medicine are presented. Chapter 2 presents an empirical analysis of medical malpractice claims arriving to the Spanish Supreme Court. The focus is on reversal rates for civil and administrative decisions. Administrative decisions appealed by the plaintiff have the highest reversal rates. The results show a bias in lower administrative courts, which tend to focus on the State side. We provide a detailed explanation for these results, which can rely on the organization of administrative judges career. Chapter 3 assesses predictors of compensation in medical malpractice cases appealed to the Spanish Supreme Court and investigates the amount of damages attributed to patients. The results show horizontal equity between administrative and civil decisions (controlling for observable case characteristics) and vertical inequity (patients suffering more severe injuries tend to receive higher payouts). In order to execute these analyses, a database of medical malpractice decisions appealed to the Administrative and Civil Chambers of the Spanish Supreme Court from 2006 until 2009 (designated by the Spanish Supreme Court Medical Malpractice Dataset (SSCMMD)) has been created. A description of how the SSCMMD was built and of the Spanish legal system is presented as well. Chapter 4 includes an empirical investigation of the effect of a monitoring system for medical malpractice claims on insurance premiums. In Italy, some regions adopted this policy in different years, while others did not. The study uses data on insurance premiums from Italian public hospitals for the years 2001-2008. This is a significant difference as most of the studies use the insurance company as unit of analysis. Although insurance premiums have risen from 2001 to 2008, the increase was lower for regions adopting a monitoring system for medical claims. Possible implications of this system are also provided. Finally, Chapter 5 discusses the main findings, describes possible future research and concludes.

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The goal of this dissertation is to use statistical tools to analyze specific financial risks that have played dominant roles in the US financial crisis of 2008-2009. The first risk relates to the level of aggregate stress in the financial markets. I estimate the impact of financial stress on economic activity and monetary policy using structural VAR analysis. The second set of risks concerns the US housing market. There are in fact two prominent risks associated with a US mortgage, as borrowers can both prepay or default on a mortgage. I test the existence of unobservable heterogeneity in the borrower's decision to default or prepay on his mortgage by estimating a multinomial logit model with borrower-specific random coefficients.

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La ricerca è mirata a valutare come l’attuazione delle politiche ambientali di Sviluppo Rurale possa contribuire al miglioramento del paesaggio, analizzando i suoi effetti territoriali. Nell’ambito del caso di studio della Regione Emilia-Romagna vengono analizzate le misure agro-ambientali e di forestazione agricola dal 1994 al 2011, comprendendo gli interventi realizzati con i Regolamenti (CEE) 2078/1992, 2080/1992 e dai Programmi di Sviluppo Rurale (PSR) 2000-2006 e 2007-2013. In particolare, sono approfonditi i fattori che determinano la partecipazione territoriale delle misure agro-ambientali, individuate a livello aziendale le motivazioni alla partecipazione per le azioni con effetto diretto sul paesaggio, valutati i conseguenti effetti tecnico-economici e analizzati gli impatti degli interventi sul paesaggio a livello territoriale, in funzione del contesto ambientale. I risultati hanno consentito di approfondire quanto già riportato nelle valutazioni istituzionali dei PSR e in letteratura scientifica, individuando i fattori determinanti della partecipazione a livello regionale. A questo scopo sono state utilizzate analisi di econometria spaziale che hanno permesso di evidenziare effetti di concentrazione territoriale delle superfici sotto impegno, in funzione delle priorità della misura e degli ordinamenti produttivi dei beneficiari. Sono stati inoltre analizzati gli impatti paesaggistici in un’area di studio ristretta a livello territoriale e aziendale: gli interventi specifici, in alcuni contesti territoriali dove è stata raggiunta una certa concentrazione delle superfici sotto impegno, hanno modificato il paesaggio rurale, differenziandolo rispetto alla matrice agricola intensiva in cui sono stati inseriti. A livello aziendale sono stati rilevati effetti significativi sull’economia dei beneficiari che scelgono di aderire a tali misure, con un diffuso effetto di riduzione della redditività. I contributi compensano in maniera differenziata i costi legati all’implementazione degli interventi in funzione della tipologia di intervento e delle scelte tecniche aziendali adottate per la loro gestione.

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In the first chapter, we consider the joint estimation of objective and risk-neutral parameters for SV option pricing models. We propose a strategy which exploits the information contained in large heterogeneous panels of options, and we apply it to S&P 500 index and index call options data. Our approach breaks the stochastic singularity between contemporaneous option prices by assuming that every observation is affected by measurement error. We evaluate the likelihood function by using a MC-IS strategy combined with a Particle Filter algorithm. The second chapter examines the impact of different categories of traders on market transactions. We estimate a model which takes into account traders’ identities at the transaction level, and we find that the stock prices follow the direction of institutional trading. These results are carried out with data from an anonymous market. To explain our estimates, we examine the informativeness of a wide set of market variables and we find that most of them are unambiguously significant to infer the identity of traders. The third chapter investigates the relationship between the categories of market traders and three definitions of financial durations. We consider trade, price and volume durations, and we adopt a Log-ACD model where we include information on traders at the transaction level. As to trade durations, we observe an increase of the trading frequency when informed traders and the liquidity provider intensify their presence in the market. For price and volume durations, we find the same effect to depend on the state of the market activity. The fourth chapter proposes a strategy to express order aggressiveness in quantitative terms. We consider a simultaneous equation model to examine price and volume aggressiveness at Euronext Paris, and we analyse the impact of a wide set of order book variables on the price-quantity decision.

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Il modello gravitazionale e' ormai diventato un "cavallo da battaglia" in economia internazionle ed e' comunemente utilizzato nella determinazione dei flussi commerciali. Recentemente, molti studi hanno mostrato l'importanza della dipendenza spaziale, che va' a considerare quegli effetti dovuti al cosiddetto "third country". Intervengono a questo scopo la modellistica e le tecniche di stima di Econometria Spaziale. Verra' fatto uso di tali tecniche allo scopo di stimare con un modello gravitazionale spaziale il commercio internazionale tra paesi dell'OCSE per un panel di 22 anni. L'obiettivo e' quindi duplice: da un lato, si andra' ad applicare le piu' moderne tecniche di Econometria Spaziale, in un campo in cui tali contributi scarseggiano. Dall'altro lato,verra' fornita una interpretazione del comportamento del commercio internazionale tra paesi dell'OCSE, approfondendo gli aspetti relativi all'effetto del"third country" e del fenomeno migratorio. Inoltre , viene proposta un'analisi che ha lo scopo di validare l'ipotesi di omissione della distanza dal modello gravitazione strutturale.

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This thesis is the result of a project aimed at the study of a crucial topic in finance: default risk, whose measurement and modelling have achieved increasing relevance in recent years. We investigate the main issues related to the default phenomenon, under both a methodological and empirical perspective. The topics of default predictability and correlation are treated with a constant attention to the modelling solutions and reviewing critically the literature. From the methodological point of view, our analysis results in the proposal of a new class of models, called Poisson Autoregression with Exogenous Covariates (PARX). The PARX models, including both autoregressive end exogenous components, are able to capture the dynamics of default count time series, characterized by persistence of shocks and slowly decaying autocorrelation. Application of different PARX models to the monthly default counts of US industrial firms in the period 1982-2011 allows an empirical insight of the defaults dynamics and supports the identification of the main default predictors at an aggregate level.

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Small-scale dynamic stochastic general equilibrium have been treated as the benchmark of much of the monetary policy literature, given their ability to explain the impact of monetary policy on output, inflation and financial markets. One cause of the empirical failure of New Keynesian models is partially due to the Rational Expectations (RE) paradigm, which entails a tight structure on the dynamics of the system. Under this hypothesis, the agents are assumed to know the data genereting process. In this paper, we propose the econometric analysis of New Keynesian DSGE models under an alternative expectations generating paradigm, which can be regarded as an intermediate position between rational expectations and learning, nameley an adapted version of the "Quasi-Rational" Expectatations (QRE) hypothesis. Given the agents' statistical model, we build a pseudo-structural form from the baseline system of Euler equations, imposing that the length of the reduced form is the same as in the `best' statistical model.

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This dissertation consists of three empirical studies that aim at providing new evidence in the field of public policy evaluation. In particular, the first two chapters focus on the effects of the European cohesion policy, while the third chapter assesses the effectiveness of Italian labour market incentives in reducing long-term unemployment. The first study analyses the effect of EU funds on life satisfaction across European regions , under the assumption that projects financed by structural funds in the fields of employment, education, health and environment may affect the overall quality of life in recipient regions. Using regional data from the European Social Survey in 2002-2006, it resorts to a regression discontinuity design, where the discontinuity is provided by the institutional framework of the policy. The second study aims at estimating the impact of large transfers from a centralized authority to a local administration on the incidence of white collar crimes. It merges a unique dataset on crimes committed in Italian municipalities between 2007 and 2011 with information on the disbursement of EU structural funds in 2007-2013 programming period, employing an instrumental variable estimation strategy that exploits the variation in the electoral cycle at local level. The third study analyses the impact of an Italian labour market policy that allowed firms to cut their labour costs on open-ended job contracts when hiring long-term unemployed workers. It takes advantage of a unique dataset that draws information from the unemployment lists in Veneto region and it resorts to a regression discontinuity approach to estimate the effect of the policy on the job finding rate of long-term unemployed workers.

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In the first chapter, I develop a panel no-cointegration test which extends Pesaran, Shin and Smith (2001)'s bounds test to the panel framework by considering the individual regressions in a Seemingly Unrelated Regression (SUR) system. This allows to take into account unobserved common factors that contemporaneously affect all the units of the panel and provides, at the same time, unit-specific test statistics. Moreover, the approach is particularly suited when the number of individuals of the panel is small relatively to the number of time series observations. I develop the algorithm to implement the test and I use Monte Carlo simulation to analyze the properties of the test. The small sample properties of the test are remarkable, compared to its single equation counterpart. I illustrate the use of the test through a test of Purchasing Power Parity in a panel of EU15 countries. In the second chapter of my PhD thesis, I verify the Expectation Hypothesis of the Term Structure in the repurchasing agreements (repo) market with a new testing approach. I consider an "inexact" formulation of the EHTS, which models a time-varying component in the risk premia and I treat the interest rates as a non-stationary cointegrated system. The effect of the heteroskedasticity is controlled by means of testing procedures (bootstrap and heteroskedasticity correction) which are robust to variance and covariance shifts over time. I fi#nd that the long-run implications of EHTS are verified. A rolling window analysis clarifies that the EHTS is only rejected in periods of turbulence of #financial markets. The third chapter introduces the Stata command "bootrank" which implements the bootstrap likelihood ratio rank test algorithm developed by Cavaliere et al. (2012). The command is illustrated through an empirical application on the term structure of interest rates in the US.