ZhiZhi Gewu

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ZhiZhi Gewu

[Write to Learn Series] The Heart and Soul Of Linear Algebra: Replacement Theorem

I am self-studying Linear Algebra following the book Linear Algebra by Stephen H. Friedberg and the syllabus Math 340: Abstract Linear Algebra from the University of Washington. In particular, I found that the proof of the Replacement Theorem is difficult. I want to share some of my experience and resources

Prediction Or What If: What's the Nature of Your Problem?

Prediction Or What If: What's the Nature of Your Problem?

With the rise of machine learning techniques, I believe we have become more susceptible to the 'law of instrument bias.' This principle suggests that if your only tool is a hammer, every problem looks like a nail. While techniques like regression, classification, and tree-based models offer tremendous value

[Write to Learn Series] You May Not Know Linear Regression Enough! Discover the Causal Effect of Credit Limit on Risk

[Write to Learn Series] You May Not Know Linear Regression Enough! Discover the Causal Effect of Credit Limit on Risk

Disclaimer: The accuracy of the information in this article is not guaranteed. The methodologies discussed are conceptual and not yet implemented in business. A common challenge in consumer loan industries is balancing risk management with credit limit increases. Credit limits, often determined by expert judgment, are typically excluded from the

Journey Through Years: Reflecting on Growth, Principles, and Future Aspirations (2024)

Since the year 2020, I have shared my reflections on the year and my expectations for the upcoming one. It’s interesting to review these notes. I would say the main difference between the older and newer reflections is that my thoughts and ideas have become more structured. In the

My 2.5 and Counting Years in Consumer Loan Credit Risk Management

Introduction: Have you ever considered the intricate balance between risk and reward in the financial world? My journey in credit risk management, particularly in managing the “Buy Now, Pay Later” (BNPL) portfolios across Indonesia, Malaysia, Philippines, Vietnam, and Brazil, has been a revelation in this regard. In my 2.5

More Choices or Fewer Choices: The Paradox of Options

Have you ever wondered whether having more choices is truly advantageous? While options grant us the power of alternatives, often leading to better deals, they can also leave us paralyzed with indecision. I vividly recall the challenges I faced when choosing a university after excelling in my exams. Throughout various

Reflecting on Business Models: A Worker’s Perspective

Have you ever wondered how some companies outperform others, or why a business model thriving in one market falls short in another? As employees, we often operate within established or proven business models without questioning their efficacy, uniqueness, or the challenges they might encounter. Although pondering these questions might not