The article argues that the slogan “no middlemen profit” misrepresents economics, showing intermediaries cut transaction costs by about 40%, bear market, inventory and capital risks, and that every “de‑intermediation” wave actually spawns new, more efficient middlemen, especially in today’s digital commerce.
This article explores how mathematical modeling, once confined to the sciences, now enriches ten humanities fields—from economics and management to sociology, psychology, and history—by providing quantitative frameworks that deepen understanding, improve predictions, and support evidence‑based decision making.
Markov Chains are mathematical models where future states depend only on the current state, not past history, and this article explains their core principles—state space, transition matrices, Markov property, steady-state distribution—and showcases practical uses in economics, biology, web ranking, queueing theory, and reinforcement learning.
Economics studies how societies allocate scarce resources to satisfy unlimited wants, exploring concepts such as scarcity, choice, efficiency versus fairness, institutional incentives, rationality versus behavior, and the interplay between micro and macro perspectives, while highlighting its practical relevance in policy, business, and personal decisions.
This article presents a visual guide to thirty classic mathematical models—spanning natural sciences, social sciences, engineering, and interdisciplinary fields—detailing their core ideas, practical applications, and key insights, illustrating how each model serves as a powerful tool for solving complex real‑world problems.
This article examines how governments and economists assign monetary values to human lives using willingness‑to‑pay, wage‑risk, and prevention‑of‑a‑death methods, presenting formulas, real‑world examples, and international VSL estimates to illustrate the strengths and limits of each approach.
This article explains the concept of log returns, their mathematical advantages over simple returns, and how they simplify financial modeling, risk management, and option pricing in economics and finance.
The article critiques the oversimplified “Trump‑style” and fabricated “Navarro‑style” economic models, exposing their lack of domain knowledge, ethical breaches, and misleading formulas, and argues for rigorous, transparent, and responsible mathematical modeling especially in the AI era.
The article examines media claims that Trump's April 2 tariff policy may have been generated by AI, reproduces ChatGPT's proposed reverse‑deficit tax model, compares it with the official USTR formula, and discusses the broader implications of AI as a parallel advisor in policy making.
Understanding the underlying assumptions—whether humans are rational economic agents, emotion‑driven animals, socially constructed beings, gene‑driven organisms, or information processors—reveals why different disciplines model decision‑making differently and highlights each perspective’s insights and limitations.
This article explores how linear algebra—through matrices, vectors, and linear transformations—underpins diverse fields such as artificial intelligence, data science, computer graphics, economics, physics, engineering, and social network analysis, illustrating its practical impact on everyday technologies and scientific models.
The Von Bertalanffy growth equation models how organisms transition from slow to rapid to stable growth by balancing synthesis and decomposition, and its principles extend beyond biology to ecology, agriculture, economics, and personal development, highlighting growth as a dynamic equilibrium rather than endless acceleration.
The article explains how opportunity cost—defined as the foregone benefit of the next best alternative—guides decisions in investing, work, and daily life, illustrating its impact with simple calculations, personal examples, and timeless quotes to help readers recognize trade‑offs.
The article uses the signaling model from economics and game theory to explain why individuals purchase expensive luxury handbags as a costly social signal that distinguishes wealth, explores equilibrium outcomes, and discusses broader applications of signaling in education, finance, and the marriage market.
The article examines how software teams manipulate bug‑rate metrics through various shortcuts, explains why cheating can appear rational from economic and psychological viewpoints, and offers management strategies to prevent and mitigate such behavior in large engineering organizations.
This article explains the concept of mediation effects, outlines how to select mediators, describes step‑by‑step testing procedures—including the classic Baron‑Kenny approach and modern bootstrap methods—and demonstrates the whole workflow with a real‑world economic example.
Logarithms, a core mathematical tool, are widely used in economics to transform multiplicative and exponential relationships into additive linear forms, facilitating analysis of production functions, utility models, growth rates, and log‑log regression, thereby simplifying estimation and interpretation of complex economic phenomena.
Derivatives, the core concept of calculus, originated from Newton’s instantaneous speed, Leibniz’s tangent, and Fermat’s extremum problems, and are defined as the limit of a function’s change ratio, linking continuity, geometry, and physics, while finding extensive applications across science, economics, and biology.
This article uses the Iberian Peninsula rebellion and the classic Nim game to illustrate fundamental concepts of game theory, linking strategic decision‑making to economics and mathematics while providing clear examples and visual diagrams for deeper understanding.
This article builds a straightforward mathematical model to explain how increasing package size reduces the per‑gram cost of products by accounting for production, packaging, and transportation expenses, revealing diminishing savings as packages become very large.
This article explores how various mathematical models—such as linear, compound interest, annuity, and optimization frameworks—are applied to national economic analysis, banking operations, securities, insurance, consumer pricing, and production management, illustrating their role in forecasting, decision‑making, and improving market competitiveness.
This article introduces major economic and financial data analysis tools—including Python with its scientific libraries, R, Stata, Matlab, EViews, SAS, and SPSS—detailing their origins, key features, typical applications, and where to find more information.
This article explains how utility theory and risk evaluation influence decision making, describing the concept of utility, different types of utility functions, and the Von Neumann‑Morgenstern method for constructing utility curves through psychological experiments.
This article traces the pivotal role of mathematics from the 18th‑century golden age of classical mechanics through Maxwell's equations, Einstein's relativity, biological modeling, game‑theoretic economics, the birth of modern computers, and the emergence of chaos and fractal theory, highlighting key figures and breakthroughs that linked abstract theory to real‑world applications.
This article explains how production factors, marginal product of labor, product pricing, and rapid technology changes shape front‑end developers' wages, offering a framework to decide which technologies are worth investing time and effort in.
The article examines the rapid growth of live‑streaming e‑commerce, explains the trust‑based dynamics of influencers, outlines standard recommendation‑system metrics such as accuracy, recall, diversity and explainability, and argues that these models fall short of long‑term user utility because they are driven by short‑term commercial goals, highlighting economic and neuroscientific perspectives on preference randomness.
This article examines how open‑source software alters the software industry's economic dynamics, from historical development patterns and monopoly tendencies to network externalities, cost structures, and the emergence of new business models that intensify competition, lower prices, and drive technological progress.
In this talk, Tsinghua professor Li Daokui uses three personal anecdotes to reveal core economic ideas—eliminating excess options, investing in one's true goals as human capital, and leveraging networks—to guide young people toward decisive, fulfilling career paths.
