Description

This Master Prompt focuses on panel-data settings in which conventional homogeneous linear specifications impose restrictions that are too strong for the substantive process or observed data structure. It guides researchers in determining whether regression slopes remain constant across cross-sectional units and time; whether relationships change smoothly with observed variables; whether selected covariates should have constant or varying coefficients; whether functional form should be imposed parametrically or estimated flexibly; and whether large sets of predictors, controls, instruments, latent factors, or multidimensional effects require regularization and specialized inference. Rather than adopting flexible models simply because they are more sophisticated, researchers are required to establish a theoretical or empirical reason for departing from the homogeneous linear benchmark.