مقایسهٔ روش‌ها

	مدل اثرات ثابت فوریه	تحلیل داده‌های پانل فوریه
حوزه	اقتصادسنجی	اقتصادسنجی
خانواده	Regression model	Regression model
سال پیدایش	2006–2012	2006 (Fourier framework); panel extensions 2010s
پدیدآور	Enders & Lee (building on Becker, Enders & Lee framework)	Becker, Enders, and Lee (Fourier unit root framework); extended to panel data by subsequent applied econometricians
نوع	Panel regression with Fourier terms	Panel regression with Fourier terms
منبع بنیادین	Enders, W., & Lee, J. (2012). A unit root test using a Fourier series to approximate smooth breaks. Oxford Bulletin of Economics and Statistics, 74(4), 574–599.	Becker, R., Enders, W., & Lee, J. (2006). A stationary test in the presence of an unknown number of smooth breaks. Journal of Time Series Analysis, 27(3), 381-409.
نام‌های دیگر	Fourier FE model, Fourier panel fixed effects, trigonometric fixed effects regression, smooth structural break fixed effects	Fourier panel regression, smooth structural break panel model, trigonometric panel data model, Fourier-flexible panel estimator
مرتبط	6	6
خلاصه	The Fourier fixed effects model extends standard panel fixed effects regression by augmenting the specification with low-frequency Fourier (trigonometric) terms. These sine and cosine components approximate unknown, smooth structural shifts in the time trend without requiring the researcher to pre-specify break dates, combining within-unit identification with flexible trend modelling.	Fourier panel data analysis embeds trigonometric sine and cosine terms into a standard panel regression to approximate smooth, gradual structural shifts in the data-generating process. Rather than assuming a sharp break at a known date, the Fourier approach lets the data reveal the timing and shape of any structural change through a flexible trigonometric approximation, while retaining the cross-sectional and time-series structure of panel data.