So sánh phương pháp

	Phương pháp Sai phân kép (Difference-in-Differences - DiD)	Nghiên cứu đối chứng ngẫu nhiên (RCT)
Lĩnh vực	Kinh tế lượng	Thiết kế thí nghiệm
Họ	Regression model	Hypothesis test
Năm ra đời	1994	1948
Người khởi xướng	Card & Krueger (canonical 1994 application); Angrist & Pischke (textbook treatment)	James Lind (early precursor, 1747); modern formulation: Austin Bradford Hill & Medical Research Council (1948)
Loại	Causal inference / panel regression	Interventional comparative study
Công trình gốc	Angrist, J. D., & Pischke, J.-S. (2009). Mostly Harmless Econometrics: An Empiricist's Companion. Princeton University Press. ISBN: 978-0691120355	Schulz, K.F., Altman, D.G., Moher, D., for the CONSORT Group (2010). CONSORT 2010 Statement: Updated Guidelines for Reporting Parallel Group Randomised Trials. BMJ, 340, c332.
Tên gọi khác	diff-in-diff, DiD, Farkların Farkı (Diff-in-Diff)	RCT, randomised controlled trial, clinical trial, Randomize Kontrollü Çalışma (RCT) Tasarımı
Liên quan	5	7
Tóm tắt	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.	A randomized controlled trial (RCT) is the gold standard experimental design in clinical and health research, in which participants are randomly allocated to a treatment group or a control group so that the effect of an intervention can be measured with the highest possible degree of internal validity. The modern parallel-group RCT was formalized by Austin Bradford Hill and the Medical Research Council in their landmark streptomycin trial of 1948, and its reporting is governed today by the CONSORT 2010 guidelines (Schulz et al., 2010).