Understanding Correlations and Copulas in Finance: An Application in Risk Portfolio Aggregation using R

I am not a fan of articles where the authors use widgets and other unrelatable examples to illustrate complex concepts. Here I will illustrate the use of copulas in finance using the example of risk aggregation to drive through the points. First, though, it is important to briefly explain the risk aggregation problem. There are plenty of texts available on the internet which go in great detail about the inner workings of copulas. My goal is to help the reader develop an intuitive understanding of how copulas are used in finance.Read More »

Machine Learning and Credit Risk (part 2) – Credit Cycle Method

The canonical method to forecasting a credit migration matrix is an econometric model: the one factor approach described in Belkin et al. (1998). This approach suggests that one might consider an approach to condition migration (transition) matrices by creating a systematic component which represents the “credit cycle” that relates the economic condition to the credit quality of a loan portfolio.  The credit cycle can be thought of as the historical pattern of credit rating shared by all borrowers in a sector or economy.Read More »

Machine Learning and Credit Risk (part 1)

Artificial Intelligence (AI) and Data Science continue their progression towards becoming mainstream and ubiquitous. This is a very exciting time for scientists, model developers, programmers, and a lot of other technically inclined professionals. But to be honest it can be confusing and overwhelming at times. We all hear terms like “AI”, “Data Science”, “Big Data”, “Machine Learning”, “Statistical Learning”, “Data Mining”, “Deep Learning”, etc., and it’s often hard to make sense of it all even for those of us who have been writing code to implement statistical models for decades. But it seems these terms are being used among people in every field and every industry. How do remote sensing professionals use data from a satellite to create land cover maps? how do certain streaming services determine what shows or movies to recommend based on your watching habits? How did Cambridge Analytica determine the poor shmucks Donald Trump should focus on? The answers to all these questions lay in machine learning algorithms.  (If interested you can find more information on the differences or definitions of all the terms mentioned above on various discussion threads on social sites like Quora, StackExchange, LinkedIn, and KDNuggets among others.)

This article will be a little more focused on the question: how can we use machine learning in areas where statistics have traditionally been employed in credit risk?

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