This thesis analyses the ratchet effect in the context of the performance scheme implemented by Brazilian tax collection in 1988 to reward tax officials for their effort in collecting taxes and uncovering tax violations, using panel data for 110 tax agencies from August 1989 to April 1993 and employing the GMM-system estimator. The estimates suggest the presence of ratchet effect, i.e., the more the tax officials do today, the more the tax officials are asked to do in the future. This result endangers the credibility of the Brazilian tax authority's incentive program as an incentive system.

This study investigates the determinants and effects of currency and asset substitution in Turkey using quarterly data from 1987:1 to 2002:4. The empirical results from the application of Johansen procedure to a four-variable system containing currency-asset substitution proxy (M2Y/M2)), real income, real exchange rate, and ratchet effect proxy (past peak values of the depreciation of the real exchange rate) suggest the presence of a single cointegration vector among the variables. The results further suggest the endogeneity of the degree of currency substitution for the parameters of the cointegration vector. According to the theory consistent and data-acceptable long-run relationship between the variables, there is a strong ratchet (hysteresis) effect in currency-asset substitution in Turkey. The study contains also the policy implications of both currency substitution and the ratchet effect arising from real exchange rate change shocks in the Turkish economy.

Submitted by Cassiano Breno Machado Alves (cbmachado@fgvmail.br) on 2013-03-25T17:36:15Z No. of bitstreams: 1 Dissertação-CassianoAlves.pdf: 1625072 bytes, checksum: e0c471a98095069d8e0e991dcf7489cf (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2013-04-03T18:51:06Z (GMT) No. of bitstreams: 1 Dissertação-CassianoAlves.pdf: 1625072 bytes, checksum: e0c471a98095069d8e0e991dcf7489cf (MD5) / Made available in DSpace on 2013-04-03T18:51:18Z (GMT). No. of bitstreams: 1 Dissertação-CassianoAlves.pdf: 1625072 bytes, checksum: e0c471a98095069d8e0e991dcf7489cf (MD5) Previous issue date: 2012-05-03 / This paper investigates the introduction of type dynamic in the La ont and Tirole's regulation model. The regulator and the rm are engaged in a two period relationship governed by short-term contracts, where, the regulator observes cost but cannot distinguish how much of the cost is due to e ort on cost reduction or e ciency of rm's technology, named type. There is asymmetric information about the rm's type. Our model is developed in a framework in which the regulator learns with rm's choice in the rst period and uses that information to design the best second period incentive scheme. The regulator is aware of the possibility of changes in types and takes that into account. We show how type dynamic builds a bridge between com- mitment and non-commitment situations. In particular, the possibility of changing types mitigates the \ratchet e ect'. We show that for small degree of type dynamic the equilibrium shows separation and the welfare achived is close to his upper bound (given by the commitment allocation).

The ratchet effect can be exploited in many types of research, yet few researchers pay attention to it. In this thesis, I investigate two examples of such effects in microfluidic devices, under the guidance of computational simulations. The first chapter provides a brief introduction to ratchet effects, electrophoresis, and swimming cells, topics directly related to the following chapters. The second chapter of this thesis studies the separation of charged spherical particles in various microfluidic devices. My work shows how to manipulate those particles with modified temporal asymmetric electric potentials. The rectification of randomly swimming bacteria in microfluidic devices has been extensively studied. However, there have been few attempts to optimize such rectification devices. Mapping such motion onto a lattice Monte Carlo model may suggest some new mathematical methods, which might be useful for optimizing the similar systems. Such a mapping process is introduced in chapter four.

The thesis deals with the synthesis of Peltzman and Higgs government growth theory and influence of the prevailing Keynesian ideology on predicative ability of these theories. Based on this theoretical synthesis thesis explains the long-term trend of increasing government power in the U.S. which is showed by all measuring methods regarding the size of governmental power. The second part of the thesis discusses the impact of the redistribution of wealth in the household sector to the size of government in the years 1979 - 2009, with an emphasis on recent crisis during 2007 - 2009. Tested hypothesis is that the redistributive processes during the last crisis were aimed mainly to U.S. residents in the area of median income. Based on a comparison of data from the years 1979 - 2009 and relating them to the crisis moment of 2007 - 2009 thesis confirms this hypothesis.

<div>My dissertation consists of three chapters in the field of managerial economics and experimental economics. The first chapter studies the ratchet effect and the possible ways to mitigate it. Specifically, I conduct a controlled experiment to test the effectiveness of job rotation in eliminating the ratchet effect. Additionally, I compare effort provision between the situation where agents are rotated exogenously and the situation where the principal rotates agents endogenously. The experiment shows that the ratchet effect is effectively reduced both when workers are informed that they will be rotated in the future and when a principal has a costly option of rotating agents.</div><div> </div><div><br></div><div>The second and third chapter are based on joint work with Prof. Yaroslav Rosokha. In the second chapter, we study a single-queue system in which human servers have discretion over the effort with which to process orders that arrive stochastically. We show theoretically that the efficient outcome in the form of high effort can be sustained in the subgame perfect equilibrium if the interactions are long term (even when each server has a short-term incentive to free ride). In addition, we show that queue visibility plays an important role in the type of strategies that can sustain high-effort equilibrium. In particular, we show that limiting feedback about the current state of the queue is beneficial if servers are patient enough. We conduct a controlled lab experiment to test the theoretical predictions and find that when the queue is visible, human subjects cooperate if the queue is long, but defect if the queue is short. We also find that cooperation is hard to achieve when the queue is not visible. </div><div><br></div><div>In the third chapter, we report another lab experiment to test the theory developed in the second chapter. In the new experiment, we provide a more natural queueing frame for the subjects rather than the neutral language used in the second chapter. We also increase the number of matches in each treatment. We find that effort increases with the expected duration of the interaction. We also find that visibility has a strong impact on the strategies that human subjects use to provide effort. As a result, providing less visibility makes servers more willing to provide high effort if they are patient enough.</div>

La nanotechnologie est un domaine en voie d'expansion qui a attiré l'attention de la recherche en raison de ses applications potentielles illimitées. La technologie des ondes millimétriques est un autre domaine intéressant qui joue un rôle de premier plan dans le développement des systèmes de communications sans fil. La combinaison de ces deux champs de recherche avancée, donne naissance à l'innovation du Dispositif Ratchet qui est une nouvelle application qui représente un vrai défi. Ce dispositif est de taille nanométrique et son concept d'opération consiste à générer une tension DC lorsque le dispositif, basé sur le gaz d'électron bidimensionnel, est rayonné par l'énergie des micro-ondes. L'objectif de cette thèse est d'essayer d'améliorer la réponse du dispositif, ce qui ouvre de nouvelles perspectives dans la fabrication des détecteurs de champ à haute fréquence et à l'échelle nanométrique. Malheureusement, les Dispositifs Ratchet actuels, basés sur des hétérostructures de semiconducteurs, réalisés jusqu'à présent fonctionnent à basse température pour assurer une grande mobilité électronique. Cette condition nécessite l'utilisation d'un setup expérimental complexe qui a un grand impact sur la tension induite et sur la reproductibilité du phénomène Ratchet observé. Dans ce contexte, le travail effectué dans le cadre de cette thèse a abordé ce problème en deux parties. La première partie concerne l'analyse électromagnétique du setup expérimental. Ceci a été réalisé par la mise en oeuvre des simulations électromagnétiques intenses. D'autre part, différentes solutions ont été proposées afin d'optimiser le setup et ainsi améliorer la tension Ratchet produite. Outre l'étude électromagnétique, certaines mesures de modulation ont été réalisées pour tester la faisabilité du Dispositif Ratchet comme un démodulateur d'amplitude. La deuxième partie de cette thèse traite l'étude de la matière qui compose le Dispositif Ratchet. Récemment, le graphène commence à envahir le monde scientifique et technologique avec ses fascinantes propriétés électroniques, tels que sa mobilité d'électrons élevée à température ambiante, où les matériaux conventionnels sont en train de confronter des obstacles. En conséquence, l'idée de fabriquer un Dispositif Ratchet à base de graphène au lieu des hétérojonctions de semiconducteurs, a été introduite. Plusieurs modèles de conception, caractérisation et mesures RF ont été accomplis en vue d'obtenir un Dispositif Ratchet fiable approprié pour de nombreuses applications pratiques à la température ambiante, dans la gamme de fréquences micro-ondes et pourraient s'étendre à la bande térahertz. / Nanotechnology is a growing field that has attracted significant research attention due to its unlimited potential applications. Millimeter wave technology is another interesting field that plays a leading role in the development of wireless communications systems. Combining these two advanced research fields together, has given rise to the innovation of the Ratchet Device which is now a new challenging application. This device has a nanoscale size and its concept of operation consists of generating a DC voltage when radiating a two-dimensional electron gas based device with microwave energy. The aim of this thesis is in trying to improve the device response and hence opening new perspectives in the fabrication of high frequency field detectors on the nanoscale level. Unfortunately, the current Ratchet Devices, based on semiconductor heterostructures, realized till now, operate at low temperatures to ensure high electron mobility. This condition necessitates the use of a complex experimental setup that has a great impact on the induced voltage and on the reproducibility of the observed Ratchet phenomenon. In this context, the work performed within the framework of this thesis has addressed this problem in two parts. The first part concerns the electromagnetic analysis of the experimental setup behavior. This has been achieved by implementing intensive full wave electromagnetic simulations. Different solutions have been proposed to optimize the setup and thus enhance the Ratchet voltage produced. In addition to the electromagnetic study, some modulation measurements have been performed to test the feasibility of the Ratchet Device as an amplitude demodulator. The second part of this thesis deals with the study of the material composing the Ratchet Device. Recently, graphene has started to invade the scientific and the technological world with its fascinating electronic properties, such as its high electron mobility at room temperature, which distinguishes it from conventional materials that typically collide with obstacles. As a result, the idea of fabricating a Ratchet Device based on graphene instead of semiconductor heterojunctions has been introduced. Several design models, characterizations and RF measurements have been performed in order to obtain a reliable Ratchet Device suitable for many practical applications at room temperature. This has been done in the microwave frequency range and can also extend to the terahertz band.

Financial intermediaries are recognized to promote the efficiency of resource allocation by mitigating problems of incentives, asymmetric information and contract incompleteness. The role played by financial intermediaries is perceived so crucial that these institutions have received all over the world the greatest attention of regulators. Differences in regulatory regimes as well as in the real economies have produced a large variety in the characteristics of financial sectors and of individual intermediaries. In particular, in different places and times it is possible to observe banking sectors more or less competitive, populated by credit intermediaries of different sizes and with different levels of specialization. This variety of institutions raises interesting questions about the features of a well functioning financial intermediation sector. These questions have inspired an important body of economic literature which, however, is still inconclusive in many aspects. This dissertation includes three studies all intending to contribute in this direction. Chapter 2 Recent empirical works have found evidence consistent with larger banks having lower incentives to collect soft information and, in particular, to lend to small firms which are typically regarded as relatively opaque borrowers. Another market segment affected by relatively high levels of opaqueness is that of long-term loans and the reason is that, as emphasized in the corporate finance literature, short-term maturities are useful for the purpose of screening and monitoring investment projects. It is therefore interesting to assess whether large and small banks differ in their propensity to issue long-term loans, a type of investigation which has not been conducted yet. The reason why small and large banks might be expected to have a different propensity to issue long-term loans has to do with two notions. First, the effectiveness of a short-term maturity as a screening and monitoring device is preserved only if parties anticipate that, when payments are due, the lender will not be willing to extend the maturity, otherwise the initial short-term loan is de facto a long-term one. The problem may rise if the liquidation of insolvent firms produces lower payoffs than their refinancing: under these circumstances, as suggested by theories on renegotiation, liquidation is not implemented no matter what is written on the contract (parties can easily avoid the inefficiency that would result from liquidation, for example by simply granting a new loan). Second, at a more specific level theories on renegotiation suggest that the ability to commit to not extend thematurity decreases with bank size.1 Small banks are therefore predicted to issue shorter-term loans and to make a better selection of projects. The results are consistent with this prediction. Controlling for other characteristics of both the demand- and the supply-side as well as for the type of guarantee supplied, small banks have lower proportions of long-term loans to total loans and lower proportions of non performing loans to total loans. It should be pointed out that this does not imply that small banks are necessarily more efficient since short-term maturities also have costs; in particular, short-term maturities can interfere with the incentives of good types by inducing short-termism (the inflation of shortterm results at the expenses of total profitability). Moreover, beyond the ability to commit other supply-side features are shown to be relevant in the determination of the maturity, at least with specific classes borrowers. In particular, the findings are also consistent with the presence of economies of scale in lending at long maturities to firms in more technical and innovative industries. Since providing the right incentives to high quality entrepreneurs and to firms in innovative sectors is more likely to be a priority in more advanced countries, a policy implication is that these economies need more the presence of large credit institutions and the more so if venture capital and stock market are of limited size. Chapter 3 As already emphasized, theories on renegotiation suggest that the ability of banks to commit to a given course of action is an important factor for efficiency and that such ability depends on observable characteristics, like bank size. An important aspect which has not been analyzed in the theoretical literature is the effect that competition among banks exert on their ability to commit. The theoretical model presented in chapter 3 tries to provide an answer to this question. More specifically, the model studies the effects of competition among banks when these are subject to dynamic commitment problems which may result in excess refinancing of insolvent borrowers (soft budget constraint) as well as in excess termination of profitable ones (ratchet effect and short-termism). The building assumption is that, because of priority schemes and relationship lending, competition is harsher for new lending than for lending to ongoing projects. The main conclusion is that there exists a trade-off between the benefits that competition brings by disciplining low quality borrowers and the costs implied by worsening the incentives of good ones. The model also allows to look at the effects of competition on stability. This is done in two ways by looking at the extent to which competition interferes with the procyclicality of the banking sector and by studying if competition may eliminate or add inefficient equilibria. The main policy implication is that the optimal level of competition of a banking system is positively related to the quality of the underlying economy. If taken together, the results of chapters 2 and 3 also provide a theory about local or regional banks which is not based on any aprioristic assumption about the technology of these type of intermediaries. As long as these institutions can be seen as banks with a relatively high market power and a relatively small size (they are often important players at a local level although of limited size), both chapters 2 and 3 suggest that these intermediaries can more easily commit to a tough stance at the refinancing stage, with positive effects on their ability to screen out bad projects but with negative effects on their ability to incentivize good types and to fund more technical and innovative firms. In other words, these institutions might promote growth at earlier stages of development, although they are not sufficient to address the incentive issues of more advanced economies. Interestingly, this interpretation of the role of local banks is totally distinct from the traditional one which is based on the aprioristic assumption that these banks are good in doing relationship lending. Chapter 4 Conflicts of interest of economic institutions carrying out a variety of functions are considered a widespread phenomenon severely limiting the efficiency that can be achieved. These worries are often taken as justification for regulations imposing transparency requirements or tougher measures like separation of functions. At the same time, contract theory suggests that the effects of opportunistic behavior can be limited by adopting appropriate incentive schemes. The third study, chapter 4, tries to understand from a theoretical point of view to what extent the use of incentive schemes can address the distortions posed by the presence of conflicts of interest. The universal bank is regarded as a (common) agent serving different clients with potentially conflicting interests: for example, it may buy assets on behalf of investors and sell assets on behalf of issuing firms. The clients offer incentive schemes to the bank and they behave non-cooperatively. The bank decides a level of effort and, when firewalls are absent, a level of collusion, modelled as a costly and unproductive redistribution of wealth among the clients (for example, the banks can at no cost sell the securities it is underwriting to the funds it manages and can do so at the price it likes). Firewalls are defined as all legal or economic devices imposing a real separation of functions and therefore preventing the bank from colluding as specified above. The main conclusion is that in the absence of firewalls the equilibrium incentive schemes are steeper. This means that the equilibrium level of effort is higher and may compensate the (ex post) inefficiency of collusion. In other words, not only appropriate incentive schemes can eliminate the distortions posed by conflicts of interest but, at least in principle, their presence may even be necessary for efficiency (this happens if effort is a public good for the two principals so that the allocation without firewalls is characterized by under-provision of effort). At the same time, the allocation without firewalls is shown to be the least efficient in the presence of one naive player who does not recognize the existence of the conflict of interest. As long as transparency requirements can be considered tools to improve market participants’ sophistication, these results suggest why and how this type of regulation can work. Moreover, the model allows to draw conclusions about the desirability of tougher regulation prescribing a more or less neat separation of functions. With sophisticated economic agents, who can address the distortions posed by conflicts of interest by choosing appropriate incentive schemes, separation of functions is unnecessary or even detrimental for efficiency. On the other hand, more or less powerful firewalls are desirable if market participants are not considered sufficiently sophisticated to be able to react to the presence of conflicts of interest and if transparency requirements cannot increase their sophistication. In few words, the optimal regulation of conflicts of interest is softer in situations involving professionals who are more likely to realize and to react by choosing an appropriate incentive scheme or, more generally, for institutions operating in advanced economies where the average level of market participants sophistication is higher.

Spatio-temporal control of the self-ordered structures by use of the time-dependent oscillatory fields of zero-time average, either deterministic (temporally regular) or noisy (temporally irregular) ones, has today become a fundamental field of multidisciplinary research in a wide variety of the highly nonlinear systems of the different physical origin. The self-ordered bistable fronts in the essentially dissipative systems of the reaction-diffusion type, that are formulated by parabolic partial differential equations, are investigated in the dissertation. The objective of the research is to investigate new possibilities of controlling the directed net motion of the self-ordered bistable fronts by the deterministic and stochastic zero-mean ac forces using computer modeling and analytic tools. In order to achieve the objective mathematical and numerical models were applied, computer software was created and new possibilities of controlling the directed net motion of bistable fronts by use of the zero-average periodic, quasi-periodic and bounded noise fields were investigated. / Savaime susidarančių lokalizuotų struktūrų valdymas deterministiškai (reguliariai) arba stochastiškai (atsitiktinai) osciliuojančiais laukais, kurių vidutinė vertė yra nulis, yra plačiai paplitęs įvairiose terpėse. Disertacijoje nagrinėjami savame susidarantys bistabilūs frontai disipatyviose sistemose, kurios aprašomos netiesinėmis parabolinėmis diferencialinėmis lygtimis su dalinėmis išvestinėmis. Disertacijos tikslas yra ištirti kryptingo bistabilių frontų dreifo valdymo nuliniais laukais galimybes, taikant kompiuterinį modeliavimą bei analitinius metodu. Tikslui pasiekti buvo sudaryti matematinis bei skaitinis modeliai, sukurta programinė įranga ir skaitiškai ištirtos savaiminių bistabilių frontų valdymo galimybės, naudojant periodinius, kvaziperiodinius ir stochastinius nulinius laukus.

Savaime susidarančių lokalizuotų struktūrų valdymas deterministiškai (reguliariai) arba stochastiškai (atsitiktinai) osciliuojančiais laukais, kurių vidutinė vertė yra nulis, yra plačiai paplitęs įvairiose terpėse. Disertacijoje nagrinėjami savame susidarantys bistabilūs frontai disipatyviose sistemose, kurios aprašomos netiesinėmis parabolinėmis diferencialinėmis lygtimis su dalinėmis išvestinėmis. Disertacijos tikslas yra ištirti kryptingo bistabilių frontų dreifo valdymo nuliniais laukais galimybes, taikant kompiuterinį modeliavimą bei analitinius metodu. Tikslui pasiekti buvo sudaryti matematinis bei skaitinis modeliai, sukurta programinė įranga ir skaitiškai ištirtos savaiminių bistabilių frontų valdymo galimybės, naudojant periodinius, kvaziperiodinius ir stochastinius nulinius laukus. / Spatio-temporal control of the self-ordered structures by use of the time-dependent oscillatory fields of zero-time average, either deterministic (temporally regular) or noisy (temporally irregular) ones, has today become a fundamental field of multidisciplinary research in a wide variety of the highly nonlinear systems of the different physical origin. The self-ordered bistable fronts in the essentially dissipative systems of the reaction-diffusion type, that are formulated by parabolic partial differential equations, are investigated in the dissertation. The objective of the research is to investigate new possibilities of controlling the directed net motion of the self-ordered bistable fronts by the deterministic and stochastic zero-mean ac forces using computer modeling and analytic tools. In order to achieve the objective mathematical and numerical models were applied, computer software was created and new possibilities of controlling the directed net motion of bistable fronts by use of the zero-average periodic, quasi-periodic and bounded noise fields were investigated.