(with t∈{0,1,4,24} and β t is the interaction effect between time step t and the L/G ratio of individual i at time step t), to a reduced model, including only the average L/G ratio and all time step contributions (Eq. (3)): 3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$ \text{expr}_{{it}} = \tau_{t} + \beta L/G_{{it}} + \epsilon_{{it}}. $$ \end{document}exprit=τt+βL/Git+εit.