05/11/2022, 14:16 Interpret Regression Coefficient Estimates - {level-level, log-level, level-log & log-log regression} - Curtis Kephart Teaching - Curtis Kephart> E conometrics Notes & R Code (UCSC Econ113)> Interpret Regression Coefficient Estimates - {level-level, log-level, level-log & log-log regression} Interpreting Beta: how to interpret your estimate of your regression coefficients (given a level-level, log-level, level-log, and log-log regression)? Assumptions before we may interpret our results: The Gauss–Markov assumptions* hold (in a lot of situations these assumptions may be relaxed - particularly if you are only interested in an approximation - but for now assume they strictly hold). * If you're interested in more details, read the discussion here, or check out your textbook. Our coefficient estimates (our estimates of below) are statistically significant and practically significant. With a multivariate model, we assume that other independent variable(s) (x_2, x_3, ... x_n) are held constant. Model Dependent or Independent Response or Variable Explanatory (y) Variable (x) Level-level Regression y x Running a Regression (Using R Statistics Software) Step-by-step example of how to do a regression using R statistics software (including the models below). I'll walk through the code for running a multivariate regression - plus we'll run a number of slightly more complicated examples to ensure it's all clear. Video 16:30 - www.youtube.com/watch?v=Ktks5K95uQM Interpretation of β Video Review Given a change in x, Given reader requests, I created short video explanations of how much do we expect y to change by? how to interpret regression estimates Δy=β1Δx Interpreting Level-Level Regression Coefficient Estimate Results “If you change x by one, we’d expect y to change by β1" We run a level-level regression and interpret the regression coefficient estimate results. Simple example of regression analysis with a level-level model. Video 5:00 - www.youtube.com/watch?v=TJACbJspao0 %Δy=100⋅β1⋅Δx “if we change x by 1 (unit), we’d expect our y variable to change by 100⋅β1 percent” Log-Level Regression x Log-Level Regression Coefficient Estimate Interpretation We run a log-level regression (using R) and interpret the regression coefficient estimate results. A nice simple example of regression analysis with a log-level model. Video 6:40 - www.youtube.com/watch?v=wXC2kViEGz8 Technically, the interpretation is the following: but the quoted interpretation is approximately true for values -0.1 < β1 < 0.1 (and it's much easier to remember.) Δy=(β1/100)%Δx Level-Log Regression y "If we increase x by one percent, we expect y to increase by (β1/100) units of y." Level-Log Regression Coefficient Estimates We run a level-log regression and help understand the regression coefficient estimates. A nice simple example of regression analysis. Video 6:50 www.youtube.com/watch?v=L9ZL6_DB4fQ Note, you cannot include obs. for which x<=0 if x is then logged. You either can't calculate the regression coefficients, or may introduce bias. %Δy=β1%Δx Log-Log Regression “if we change x by one percent, we’d expect y to change by β1 percent” Note, you cannot include obs. for which x<=0 if x is logged. You either can't calculate the regression coefficients, or may introduce bias. Log-Log Regression Coefficient Estimate Results We do a log-log regression and explain the regression coefficient estimate results. Simple example of regression analysis with a log-log model. Video 5:30 www.youtube.com/watch?v=NZCSt9Wkpkl Č ą gif[1].latex_y (0k) Curtis K, Jun 12, 2013, 4:47 PM v.1 ď Comments You do not have permission to add comments. Sign in | Report Abuse | Powered By Google Sites https://sites.google.com/site/curtiskephart/ta/econ113/interpreting-beta 1/1