The purpose of this study is to examine the impact of management altering its tone in communications on participants' perceptions of management credibility. Management's tone in communicating with participants was manipulated using communications from management under two treatment conditions. In period one of the study management's tone was manipulated within the management statement on internal controls as required by the Public Company Accounting Oversight Board's (PCAOB) Auditing Standards No. 2. In period one, participants had no knowledge of management's prior forecasting accuracy. Consistent with predicted hypotheses, the findings reveal that management can increase its credibility with participants by communicating its empathy, responsiveness, and understanding. Management's increased credibility was measured using both a validated credibility scale and by examining participants' reliance on management's forecasts. In period two of the study all participants had knowledge of management's forecast failure in period one. The results from period two found that tone could impact the rating of management's credibility when management had previously failed to meet a forecast but that tone had no impact on participant's changes in their earnings per share estimates after management had previously failed to meet a forecast.

Research into political satire programs show that they can be informative in the same way traditional news inform citizens and that the audience trust the information told by satirists. The political satire program Last Week Tonight with John Oliver has inspired the phenomenon ‘the John Oliver Effect’ due to comedian John Oliver’s ability to influence the world of politics and beyond with his in-depth investigations in serious subjects. In the author’s previous research Last Week Tonight has been portrayed by the media as being a credible source despite being the work of a comedian. This study therefore aimed to research what it is that makes Oliver and Last Week Tonight a credible source and whether some aspects of the reporting can be seen as communication campaign. With the theory of source credibility as part of its core, this study used the method of multimodality to ascertain that the main aspect that spoke to Oliver’s credibility was his perceived trustworthiness rather that his expertise or attractiveness. Using the same method but with the theory of communication campaign as part of its core, the study also ascertained that the program in general possessed some characteristics of a communication campaign but to be completely successful an episode had to possess all characteristics of a communication campaign. Merging this with previous research would indicate that subjectivity – Oliver’s authenticity and honest opinions and feelings – play an important part in his perceived credibility.

One basic problem in statistical sciences is to understand the relationships among multivariate outcomes. Although it remains an important tool and is widely applicable, the regression analysis is limited by the basic setup that requires to identify one dimension of the outcomes as the primary measure of interest (the "dependent" variable) and other dimensions as supporting this variable (the "explanatory" variables). There are situations where this relationship is not of primary interest. For example, in actuarial sciences, one might be interested to see the dependence between annual claim numbers of a policyholder and its impact on the premium or the dependence between the claim amounts and the expenses related to them. In such cases the normality hypothesis fails, thus Pearson's correlation or concepts based on linearity are no longer the best ones to be used. Therefore, in order to quantify the dependence between non-normal outcomes one needs different statistical tools, such as, for example, the dependence concepts and the copulas. This thesis is devoted to modelling dependence with applications in actuarial sciences and is divided in two parts: the first one concerns dependence in frequency credibility models and the second one dependence between continuous outcomes. In each part of the thesis we resort to different tools, the stochastic orderings (which arise from the dependence concepts), and copulas, respectively. During the last decade of the 20th century, the world of insurance was confronted with important developments of the a posteriori tarification, especially in the field of credibility. This was dued to the easing of insurance markets in the European Union, which gave rise to an advanced segmentation. The first important contribution is due to Dionne & Vanasse (1989), who proposed a credibility model which integrates a priori and a posteriori information on an individual basis. These authors introduced a regression component in the Poisson counting model in order to use all available information in the estimation of accident frequency. The unexplained heterogeneity was then modeled by the introduction of a latent variable representing the influence of hidden policy characteristics. The vast majority of the papers appeared in the actuarial literature considered time-independent (or static) heterogeneous models. Noticeable exceptions include the pioneering papers by Gerber & Jones (1975), Sundt (1988) and Pinquet, Guillén & Bolancé (2001, 2003). The allowance for an unknown underlying random parameter that develops over time is justified since unobservable factors influencing the driving abilities are not constant. One might consider either shocks (induced by events like divorces or nervous breakdown, for instance) or continuous modifications (e.g. due to learning effect). In the first part we study the recently introduced models in the frequency credibility theory, which can be seen as models of time series for count data, adapted to actuarial problems. More precisely we will examine the kind of dependence induced among annual claim numbers by the introduction of random effects taking unexplained heterogeneity, when these random effects are static and time-dependent. We will also make precise the effect of reporting claims on the a posteriori distribution of the random effect. This will be done by establishing some stochastic monotonicity property of the a posteriori distribution with respect to the claims history. We end this part by considering different models for the random effects and computing the a posteriori corrections of the premiums on basis of a real data set from a Spanish insurance company. Whereas dependence concepts are very useful to describe the relationship between multivariate outcomes, in practice (think for instance to the computation of reinsurance premiums) one need some statistical tool easy to implement, which incorporates the structure of the data. Such tool is the copula, which allows the construction of multivariate distributions for given marginals. Because copulas characterize the dependence structure of random vectors once the effect of the marginals has been factored out, identifying and fitting a copula to data is not an easy task. In practice, it is often preferable to restrict the search of an appropriate copula to some reasonable family, like the archimedean one. Then, it is extremely useful to have simple graphical procedures to select the best fitting model among some competing alternatives for the data at hand. In the second part of the thesis we propose a new nonparametric estimator for the generator, that takes into account the particularity of the data, namely censoring and truncation. This nonparametric estimation then serves as a benchmark to select an appropriate parametric archimedean copula. This selection procedure will be illustrated on a real data set.

In this thesis, we first go through classical results from the field of credibility theory. One of the most well-known models in the field is the Büuhlmann-Straub model. The model is relatively straightforward to apply in practice and is widely used. A major advantage of the model is its simplicity and intuitive dependency on its model parameters. From our perspective, the main drawback is the assumption regarding uncorrelated data. We show that the correlation can be used to cancel observational noise and therefore obtain more accurate estimators. This leads to an extended credibility formula that contains the Bühlmann-Straub model as a special case. This comes at the cost of introducing singularities which may cause the estimator to behave unexpectedly under certain circumstances. Further research is needed to better understand how often the circumstances are met in practice and if transforming the optimal weights could be a way forward in such cases. Finally, a simulation study based on real-world data shows that the proposed model outperforms the Bühlmann-Straub model.

Revisorns roll har på senare tid kommit att innefatta mer än att säkerställa de finansiella talensriktighet. En stor del av revisorns arbetsuppgifter handlar om att tillstå sina klienter med alltyp av rådgivning. En följd av revisorns utökade arbetsuppgifter är att det ställer krav pårevisorn att inneha kunskap om en rad olika ämnen. Denna utveckling har kommit attinnebära att allmänheten anses ha höga förväntningar på revisorn i dess yrkesroll.Tidigare forskning visar att bedrägerier inom organisationer har ökat på senare tid och att dethar kommit att bli ett ökat problem i samhället. I och med indikationer på att bedrägerier iorganisationer har ökat anses allmänheten också ha förväntningar på att revisorn skallupptäcka bedrägerier när de utför revision. Revisorerna själva anser däremot inte att det är ettsyfte med revisionen att upptäcka eventuella bedrägerier. Forskare menar dock attallmänhetens förväntningar är så pass höga att revisorerna måste ta hänsyn till detta krav.Tidigare forskning samt de tillfrågade revisorerna bekräftar att bedrägerier i företag är mycketproblematiska att upptäcka med hänsyn till det faktum att de inte enskilt har någon storpåverkan på de finansiella räkenskaperna för ett bolag.Meningsskiljaktigheter råder mellan revisorerna och användarna kring revisorns roll och bådetidigare forskning samt de revisorer jag har intervjuat i denna studie vittnar om att det råderett förväntningsgap mellan de olika parterna. En vanlig missuppfattning menar revisorerna imin undersökning är att allmänheten tror att revisorerna reviderar och kontrollerar pådetaljnivå. I både tidigare forskning samt empiriskt underlag finner jag uppfattningen attkunskapen kring revisorns roll måste öka. Tidigare forskning och de tillfrågaderespondenterna är överens om att information är huvudnyckeln till att minska deförväntningsgap som råder och som från revisorernas sida uppfattas som mycket olyckligt.Studien har gjorts i syfte att med kvalitativa semistrukturerade intervjuer med revisorerklargöra hur revisorerna själva ser på sin roll att upptäcka bedrägerier i organisationer.Studien består sammanlagt av åtta respondenter representerade på fyra revisionsbyråer varavtre stycken är stora revisionsbolag och en mindre revisionsbyrå. Resultatet av denna studievisar att revisorerna är överens om att upptäcka bedrägerier inte är ett huvudmål medrevisionen utan utgör endast en del. Revisorerna i studien menar att det är deras uppgift attgranska utifrån väsentlighet och risk. Samtliga respondenter menar att det är ledningensansvar att upptäcka bedrägerier men framförallt betonar de vikten av att förebyggabedrägerier med hjälpa av goda interna kontroller. / Program: Civilekonomprogrammet