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Developing a Credit Scoring Model Using Social Network Analysis Developing a Credit Scoring Model Using Social Network Analysis Ahmad Abd Rabuh UP821483 This thesis is submitted in fulfilment of the requirements for the award of the degree of Doctor of Philosophy in the School of Business and Law at the University of Portsmouth November 2020 1 Author’s Declaration Whilst registered as a candidate for the above degree, I have not been registered for any other research award. The results and conclusions embodied in this thesis are the work of the named candidate and have not been submitted for any other academic award. Signature: Name: Ahmad Abd Rabuh Date: the 30th of April 2020 Word Count: 63,809 2 Acknowledgements As I witness this global pandemic, my greatest gratitude goes to my mother, Hanan, for her moral support and encouragement through the good, the bad and the ugly. During the period of my PhD revision, I received mentoring and help from my future lifetime partner, Kawthar. Also, I have been blessed with the help of wonderful people from Scholars at Risk, Rose Anderson and Sarina Rosenthal, who assisted me in the PhD application and scholarship processes. Additionally, I cannot be thankful enough to the Associate Dean of Research, Andy Thorpe, who supported me in every possible way during my time at the University of Portsmouth. Finally, many thanks to my supervisors, Mark Xu and Renatas Kizys for their continuous guidance. 3 Developing a Credit Scoring Model Using Social Network Analysis Table of Contents Abstract ......................................................................................................................................... 10 CHAPTER 1: INTRODUCTION ................................................................................................. 12 1.1. Research Questions ........................................................................................................ 16 1.2. Aims and Objectives ...................................................................................................... 16 1.3. Contribution ................................................................................................................... 17 1.4. Organisation of Chapters ................................................................................................ 18 CHAPTER 2: LITERATURE REVIEW ...................................................................................... 21 2.1. Regulations on Assessing Creditworthiness .................................................................. 21 2.1.1. International Financial Reporting Standards 9 ....................................................... 22 2.1.2. Markets in Financial Instruments Directive II ........................................................ 22 2.1.3. General Data Protection Regulation ....................................................................... 23 2.1.4. Payments Services Directive II ............................................................................... 23 2.1.5. Basel Accords ......................................................................................................... 24 2.2. Credit Scoring ................................................................................................................ 24 2.2.1. Scope of Assessment............................................................................................... 25 2.2.2. Credit Pricing .......................................................................................................... 26 2.2.3. Traditional Criteria.................................................................................................. 27 2.2.4. Behavioural Finance ............................................................................................... 30 2.2.5. Dynamic Criteria ..................................................................................................... 50 2.2.6. Summary of Credit Scoring Criteria ....................................................................... 52 2.3. Credit Risk Models......................................................................................................... 54 2.3.1. Parametric Models .................................................................................................. 56 2.3.2. Non-Parametric Models .......................................................................................... 60 2.3.3. Summary of Previous Results ................................................................................. 67 2.3.4. Dynamic Modelling ................................................................................................ 69 2.3.5. Credit Analytics ...................................................................................................... 70 2.3.6. Depiction of Credit Models .................................................................................... 71 4 2.4. Networks ........................................................................................................................ 72 2.4.1. Introduction to Social Networks ............................................................................. 72 2.4.2. Structure of Social Networks .................................................................................. 73 2.4.3. Community Detection ............................................................................................. 74 2.4.4. Social Network Models........................................................................................... 75 2.4.5. Social Networks in Credit ....................................................................................... 75 2.4.6. Other Use Cases of Social Networks ...................................................................... 77 .2.4.7 Systems in Social Network Analysis ...................................................................... 79 2.5. Summary ........................................................................................................................ 83 2.6. Gap ................................................................................................................................. 85 CHAPTER 3: PRACTICAL SYSTEMS AND TOOLS .............................................................. 88 3.1. Peer-to-Peer .................................................................................................................... 88 3.2. Non-banking Lenders ..................................................................................................... 90 3.3. Digital Banks .................................................................................................................. 92 3.4. Credit Referencing Agencies ......................................................................................... 92 3.4.1. Credit Bureaus ........................................................................................................ 96 CHAPTER 4: METHODOLOGY AND DATA ........................................................................ 102 4.1. Research Design and Framework ................................................................................. 102 4.2. Research Philosophy .................................................................................................... 104 4.3. Qualitative Method: Interviews .................................................................................... 105 4.3.1. Sample Selection ................................................................................................... 105 4.3.2. Data Collection ..................................................................................................... 108 4.4. Quantitative Testing for Credit Score Modelling ......................................................... 109 4.4.1. Credit Scoring Model ............................................................................................ 110 4.4.2. Data Selection ....................................................................................................... 111 4.4.3. Data Description ................................................................................................... 112 4.4.4. Data Preparation.................................................................................................... 114 4.4.5. Models and Tests .................................................................................................. 114 4.4.6. Data Treatment...................................................................................................... 119 4.4.7. Evaluation Methods .............................................................................................. 121 CHAPTER 5: RESULTS, FINDINGS AND DISCUSSION ..................................................... 124 5.1. Interview Findings........................................................................................................ 124 5.1.1. Description ............................................................................................................ 125 5.1.2. Systems and Models ............................................................................................. 126 5 5.2. Modelling and Testing ................................................................................................. 130 5.2.1. Exploratory Data Analysis (EDA) ........................................................................ 130 5.2.2. Data Wrangling ..................................................................................................... 134 5.2.3. Pre-processing ......................................................................................................
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