So sánh phương pháp

	Thí nghiệm tự nhiên theo cấu trúc thừa số	Phương pháp Sai phân kép (Difference-in-Differences - DiD)
Lĩnh vực	Thiết kế thí nghiệm	Kinh tế lượng
Họ	Process / pipeline	Regression model
Năm ra đời	1920s (factorial origins, Fisher); natural experiment formalization 1990s–2000s; factorial natural experiment usage widespread 2000s–present	1994
Người khởi xướng	Extension of natural experiment tradition (Dunning, Angrist & Pischke) combined with factorial design logic (Fisher)	Card & Krueger (canonical 1994 application); Angrist & Pischke (textbook treatment)
Loại	Quasi-experimental research design	Causal inference / panel regression
Công trình gốc	Dunning, T. (2012). Natural Experiments in the Social Sciences: A Design-Based Approach. Cambridge University Press. ISBN: 978-1107698000	Angrist, J. D., & Pischke, J.-S. (2009). Mostly Harmless Econometrics: An Empiricist's Companion. Princeton University Press. ISBN: 978-0691120355
Tên gọi khác	factorial quasi-experiment, multi-factor natural experiment, factorial exogenous variation design	diff-in-diff, DiD, Farkların Farkı (Diff-in-Diff)
Liên quan	4	5
Tóm tắt	A factorial natural experiment exploits naturally occurring exogenous variation across two or more factors simultaneously, allowing researchers to estimate main effects and interactions without random assignment. Natural events, policy changes, or institutional rules create treatment conditions that approximate a factorial structure, enabling causal inference in observational settings where controlled experimentation is infeasible or unethical.	Difference-in-Differences is a causal-inference method that estimates the effect of an intervention by comparing how a treatment group and a control group change over time. Made famous by Card and Krueger's 1994 minimum-wage study and developed in Angrist and Pischke's Mostly Harmless Econometrics, it isolates the treatment effect as the difference between the two groups' before-after changes.