Secondary data

Résumé

Secondary data refers to data that is collected by someone other than the primary user. Common sources of secondary data for social science include censuses, information collected by government departments, organizational records and data that was originally collected for other research purposes. Primary data, by contrast, are collected by the investigator conducting the research. Secondary data analysis can save time that would otherwise be spent collecting data and, particularly in the case of quantitative data, can provide larger and higher-quality databases that would be unfeasible for any individual researcher to collect on their own. In addition, analysts of social and economic change consider secondary data essential, since it is impossible to conduct a new survey that can adequately capture past change and/or developments. However, secondary data analysis can be less useful in marketing research, as data may be outdated or inaccurate. Sources of secondary

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https://en.wikipedia.org/wiki/Secondary_data

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Essays on Capital Calculation in Insurance

Mathieu Jacques David Cambou

In order to be able to bear the risk they are taking, insurance companies have to set aside a certain amount of cushion that can guarantee the payment of liabilities, up to a dened probability, and thus to remain solvent in case of bad events. This amount is named capital. The calculation of capital is a complex problem. To be sustainable, capital must consider all possible risk sources that may lead to losses among assets and liabilities of the insurance company, and it must account for the likelihood and the eect of these bad (and usually extreme) events that could occur to the risk sources. Insurance companies build models and tools in order to perform this capital calculation. For that, they have to collect data, build statistical evidence, build mathematical models and tools in order to eciently and accurately derive capital. The papers exposed in this thesis deal with three major diculties. First, the uncertainty behind the choice of a specic model and the quantication of this uncertainty in terms of additional capital. The use of external scenarios, i.e. opinions on the likelihood of some events happening, allows to build a coherent methodology that make the cushion more robust against wrong model specication. Second, the computational complexity in using these models in an industrialized environment, and numerical methods available for increasing their computational eciency. Most of these models cannot provide an analytical formula of capital. Consequently, one has to approximate it via simulation methods. Considering the high number of risk sources and the complexity of insurance contracts, these methods can be slow to run before providing a reasonable accuracy. This often makes these models unusable in practical cases. Enhancements of classical simulation methods are presented in the aim of making these approximations faster to run for the same level of accuracy. Third, the lack of reliable data and the high complexity of problems with long time horizons, and statistical methods for identifying and building reliable proxies in such cases. A typical example is life-insurance contracts that imply being exposed to multiple risks sources over a long horizon. Such contracts can in fact be approximated wisely by proxies that can capture the risk over time.

EPFL2016

Chargement

We live in the "inverse-privacy" world, where service providers derive insights from users' data that the users do not even know about. This has been fueled by the advancements in machine learning technologies, which allowed providers to go beyond the superficial analysis of users' transactions to the deep inspection of users' content. Users themselves have been facing several problems in coping with this widening information discrepancy. Although the interfaces of apps and websites are generally equipped with privacy indicators (e.g., permissions, policies, ...), this has not been enough to create the counter-effect. We particularly identify three of the gaps that hindered the effectiveness and usability of privacy indicators: - Scale Adaptation: The scale at which service providers are collecting data has been growing on multiple fronts. Users, on the other hand, have limited time, effort, and technological resources to cope with this scale. - Risk Communication: Although providers utilize privacy indicators to announce what and (less often) why they need particular pieces of information, they rarely relay what can be potentially inferred from this data. Without this knowledge, users are less equipped to make informed decisions when they sign in to a site or install an application. - Language Complexity: The information practices of service providers are buried in complex, long privacy policies. Generally, users do not have the time and sometimes the skills to decipher such policies, even when they are interested in knowing particular pieces of it. In this thesis, we approach usable privacy from a data perspective. Instead of static privacy interfaces that are obscure, recurring, or unreadable, we develop techniques that bridge the understanding gap between users and service providers. Towards that, we make the following contributions: - Crowdsourced, data-driven privacy decision-making: In an effort to combat the growing scale of data exposure, we consider the context of files uploaded to cloud services. We propose C3P, a framework for automatically assessing the sensitivity of files, thus enabling realtime, fine-grained policy enforcement on top of unstructured data. - Data-driven app privacy indicators: We introduce PrivySeal, which involves a new paradigm of dynamic, personalized app privacy indicators that bridge the risk under- standing gap between users and providers. Through PrivySeal's online platform, we also study the emerging problem of interdependent privacy in the context of cloud apps and provide a usable privacy indicator to mitigate it. - Automated question answering about privacy practices: We introduce PriBot, the first automated question-answering system for privacy policies, which allows users to pose their questions about the privacy practices of any company with their own language. Through a user study, we show its effectiveness at achieving high accuracy and relevance for users, thus narrowing the complexity gap in navigating privacy policies. A core aim of this thesis is paving the road for a future where privacy indicators are not bound by a specific medium or pre-scripted wording. We design and develop techniques that enable privacy to be communicated effectively in an interface that is approachable to the user. For that, we go beyond textual interfaces to enable dynamic, visual, and hands-free privacy interfaces that are fit for the variety of emerging technologies.

EPFL2017

Chargement

Essays on Capital Calculation in Insurance

Mathieu Jacques David Cambou

EPFL2016

EPFL2017