Contributed two research-driven markdown reports to the d2cml-ai/CausalAI-Course repository, focusing on advancing the course’s knowledge base and supporting future research planning. Delivered a detailed analysis of Airbnb price prediction, integrating machine learning and sentiment analysis to evaluate methodology, strengths, and weaknesses. Produced a comprehensive summary of Double/Debiased Machine Learning for treatment and structural parameter estimation, outlining causal inference techniques and future research directions. Emphasized research analysis, technical writing, and research summary skills throughout the work. All deliverables were peer-ready, well-structured in Markdown, and designed to enhance learning outcomes for users of the CausalAI-Course repository.