Dynamic graphics in Excel for teaching statistics: understanding the probability density function
In this article, we show a dynamic graphic in Excel that is used to introduce an important concept in our subject, Statistics I: the probability density function. This interactive graphic seeks to facilitate conceptual understanding of the main aspects analysed by the learners.
The formation of aggregate expectations: wisdom of the crowds or media influence?
ABSTRACTThe general elections of 2015 in Spain were elections of change. Two new parties for which voters had no previous historical reference points burst onto the parliamentary scene. Two (partially) opposed theories vie to offer an explanation as to how voters build their aggregate electoral expectations. In this paper, we investigate which mechanism has the greatest influence on the formation of expectations: published opinion or social interactions. Likewise, we also study if there is an ideological bias in the voters’ perception of the future results of the electoral battle. Based on analysis of microdata from a survey (sample size = 14,262) conducted in Spain on the occasion of the g…
Combining Benford's Law and machine learning to detect money laundering. An actual Spanish court case.
Abstract Objectives This paper is based on the analysis of the database of operations from a macro-case on money laundering orchestrated between a core company and a group of its suppliers, 26 of which had already been identified by the police as fraudulent companies. In the face of a well-founded suspicion that more companies have perpetrated criminal acts and in order to make better use of what are very limited police resources, we aim to construct a tool to detect money laundering criminals. Methods We combine Benford’s Law and machine learning algorithms (logistic regression, decision trees, neural networks, and random forests) to find patterns of money laundering criminals in the conte…