Aufdeckung von Versicherungsbetrug bei Kfz-Schäden mit Hilfe des Benford-Tests

The German Insurance Association estimates a yearly amount of damage of € 1.5?bn to German motor vehicle insurance companies because of systematic fraud by insurance holders. It is supposed that about 10% of submitted claim applications contain manipulated data, therefore insurance companies are forced to complete a detailed and cost intensive case-by-case review of each single application. An alternative method to detect fraud in empiric data is the method of digital analysis based on Benford’s law. The Benford method uses a mathematical law of specific logarithmic distribution attributes of first digits. According to this approach, the data of a Benford set confirm with the expected digit distribution, if the data is not manipulated, whereas fraudulent interventions lead to a deviation from Benford’s law. Hence, until now there has not been any investigation whether the Benford method can also be applied on insurance data. The present article analyses a dataset consisting of more than 120,000 damage claim applications to answer this question as well as to identify the impact of specific characteristics on the probability of fraud contained in claim applications, such as the repair of the vehicle in a franchised or an independent workshop, the vehicle brand or the examination by insurance companies experts. Indeed it could be shown that Benford’s Law is only applicable on second digits of insurance data, but delivers very strong results here: All results of the considered characteristics could be verified by plausible arguments. For this reason insurance companies can benefit from making use of the Benford method to identify those claim applications with a high probability of fraud, which should then be reviewed in more detail so that resources can be allocated in a much more cost efficient way.     

Taxation and parental time allocation under different assumptions on altruism

This paper examines the effects of labor income taxation on parental time allocation in an OLG model in which child care arrangements, that is the combination of parental and non-parental time, matter for human capital accumulation. We show that the sign of the impact of labor income taxation on parental time with children and on growth critically depends on the assumption on the altruistic motives behind the choice of devoting time to children.     

Return dispersion and expected returns

This paper proposes a two-factor asset-pricing model that incorporates market return and return dispersion. Consistent with this model, we find that stocks with higher sensitivities to return dispersion have higher average returns, and that return dispersion carries a significant positive price of risk. In particular, the return dispersion factor dominates the book-to-market factor in explaining cross-sectional expected returns. The return dispersion model outperforms the CAPM, MVM, IVM, and FF-3M when using a set of 5×5 test portfolios constructed from NYSE and AMEX stock returns from August 1963 to December 2005. Return dispersion continues to play an important role in explaining the cross-sectional variation of expected returns, even when market volatility, idiosyncratic volatility, size, book-to-market factors, and a momentum factor are included. This study sheds some light on the ability of return dispersion to explain expected returns beyond the standard asset-pricing factors. Our finding suggests that return dispersion captures two dimensions of systematic risk: the business cycle and fundamental economic restructuring.     

Did a Public Campaign Influence Debit Card Usage? Evidence from the Netherlands

Did consumers change their payment behaviour after being exposed to a public campaign that encouraged them to use their debit cards more often? We analysed the impact of such a campaign that started in 2007, using debit card transaction data between 2005 and 2013. The overall results show positive effects of the national campaign to promote debit card usage, both in the short and in the long run. The results suggest that high campaign intensity aimed at consumers had a positive impact, as did a focus on certain large retail chains. Interventions aimed at increasing debit card acceptance by retailers were effective to some extent. Providing information to retailers about the benefits of debit card acceptance led to higher card acceptance, but no proof was found for the effectiveness of financial incentives for retailers.     

<Emphasis Type="Italic">K</Emphasis>-fold cross validation performance comparisons of six naive portfolio selection rules: how naive can you be and still have successful out-of-sample portfolio performance?

Recent research reports that optimal portfolio selection models often perform worse than equal-weight naive diversification in out-of-sample testing. This paper extends this line of inquiry by comparing the out-of-sample performance of the equal-weight naive strategy to the out-of-sample performance of five alternative naive strategies, each of which derives from a simple heuristic that does not require any optimization. Out-of-sample portfolio performance is assessed by mean, standard deviation, skewness, and Sharpe ratio; k-fold cross validation is used as the out-of-sample testing mechanism. The results indicate that the proposed naive heuristic rules exhibit strong out-of-sample performance, in most cases superior to the equal-weight naive strategy. These findings are consequential for at least two reasons: first, if these simple heuristic-based rules outperform the equal-weight naive strategy, then by transitivity they can outperform the mean–variance- and shortfall-optimal portfolio rules that have been shown in the literature to be inferior to the equal-weight naive rule, which further emphasizes the out-of-sample fragility of “optimal” methods; and second, among naive diversification strategies, some appear more robust in out-of-sample testing than others, hence the proposed methods may be useful when forming mixed portfolio selection models wherein a naive strategy is combined with an optimal strategy to improve performance.     

Product elimination: A barrier to successful financial service sector company mergers?

The UK's financial service sector is in a process of consolidation predominately via merger and acquisition activity. Driving this process is the desire to reduce costs, increase efficiency and acquire larger customer volumes. This may result in the amalgamation of product management functions and product portfolios, leading inevitably to the need for product rationsalisation. A key controlling factor within this is the inability easily to eliminate financial service products. This may jeopardise the organisation's ability to gain the objectives that have driven the merger/acquisition action. Two key factors were seen to hinder the portfolio amalgamation process. First, the incompatibility of IT-based product management systems. Secondly, the existence of a ‘knowledge gap’ which made it harder to plan and implement effectively large-scale product elimination and portfolio amalgamation. It is likely that this will lead to higher than desired operating costs, duplication in product and service function, and loss of freedom in managing customers.     

Click me: an examination of the impact size,color, and design has on banner advertisements generating clicks

Banner advertisements are either ignored or criticized and rarely receive clicks. However, companies tend to use consistent messages but vary the visual characteristics to entice clicks. This study examined 22,978 instances of banner placements measured in weeks from an insurance company in 2016. Results point to the 300 × 250 size, blue ads, and static design generating more clicks than larger sizes, red ads, and animated designs.     

Constructing the Economy: The Role of Construction Sector in India’s Growth

On empirically examining the importance of construction sector in propelling economic growth rate in India, the study has found that in the presence of the dominant influence of capital stock, the impact of the construction sector gets blurred or neutralized. Once capital stock is dropped from the model, the construction sector emerges as a significant determinant of economic growth, while other financial variables such as interest rate and non-food bank credit including the financial liberalization dummy do not play significant roles in economic growth. However, from an investigation of the impact of the construction sector on economic growth through the channel of employment, it is seen that the construction sector might be impacting the growth rate through increasing employment and thereby increasing the aggregate output in the economy.     

Leading the herd: evidence from mutual funds’ buy and sell decisions

This article investigates whether a mutual fund’s performance is related to its herding behavior. Using the methodology of Sias (Rev Finance Stud 17:165–206, 2004), we develop a measure to capture the magnitude that a fund’s buy (sell) decisions are leading other funds’ buys (sells), and find that a fund’s performance is positively (negatively) related to its “buy leading” (“sell leading”). We interpret these findings as evidence that “buy leaders” (“sell leaders”)’ performance benefits (suffers) from the positive (negative) price effect associated with buy (sell) herds. Additionally, we find a positive relationship between fund performance and valuation-motivated “buy leading”, while we find weak evidence on the relationship between performance and valuation-motivated “sell leading”. We interpret these results as evidence that leading funds’ outperformance is due, in part, to their ability to value stocks.     

Liquidity and market incompleteness

This note shows that according to Lippman and McCall’s (Am Econ Rev 76, 43–55, 1986) operational definition of liquidity, incomplete markets are a necessary condition for illiquidity. This note is a revised subset of a larger paper that circulated under the name of “Liquidity as an Insurance Problem” (Zurita 2001). I am grateful to Luis Ahumada, David K. Levine, Raimundo Soto, Gert Wagner, Federico Weinschelbaum and seminar participants at UCLA, Summer Meeting of the Econometric Society, Banco Central de Chile, LACEA, Jornadas de Economía del Banco Central del Uruguay, and ILADES, for their helpful comments, as well as the feedback of an anonymous referee. Financial support from Vicerrectoría Académica de la Pontificia Universidad Católica de Chile is gratefully acknowledged.