قارن الطرق

	البحث الكمي الرصدي القائم على اللجان	نموذج التأثيرات الثابتة
المجال	تصميم البحث	الاقتصاد القياسي
العائلة	Process / pipeline	Regression model
سنة النشأة	1960s–1980s (formalized in econometrics); widely adopted in social sciences by 1990s	1971–1978
صاحب الطريقة	Established through econometrics literature; foundational contributions by Cheng Hsiao, Zvi Griliches, and Marc Nerlove	Mundlak (1978); Nerlove (1971); classical panel econometrics
النوع	Quantitative observational longitudinal design	Panel regression estimator
المصدر التأسيسي	Hsiao, C. (2003). Analysis of Panel Data (2nd ed.). Cambridge University Press. ISBN: 978-0521522717	Baltagi, B. H. (2021). Econometric Analysis of Panel Data (6th ed.). Springer. ISBN: 978-3030538002
الأسماء البديلة	panel observational study, longitudinal observational panel design, panel survey research, repeated-measures observational design	FE model, within estimator, least squares dummy variable, LSDV regression
ذات صلة	4	5
الملخص	Panel-based observational quantitative research follows the same individuals, organizations, or units across two or more time points without experimentally manipulating any condition. By combining the within-unit depth of longitudinal tracking with the numerical precision of quantitative measurement, it enables researchers to study change over time, detect lagged effects, and control for stable unobserved characteristics — all while maintaining the ethical simplicity of pure observation.	The fixed effects (FE) model is the workhorse estimator for panel data when unobserved unit-specific characteristics are suspected to correlate with the regressors. By absorbing each entity's time-invariant heterogeneity into a separate intercept, FE isolates the causal effect of within-unit variation and eliminates omitted-variable bias from time-constant confounders.