The zip file contains the necessary codes and data files to reproduce the major findings presented in the submitted manuscript "Effects of Time-Varying Predictors on Web Survey Response" by Qixiang Fang, Joep Burger, Ralph Meijers and Kees van Berkel.  In the "Google Trends Data Retrievel and Calibration" folder, you can find two R code files. Using the "Daily GT Data Retrieval.R" file, you can download the Google Trends data we used for the study. Using the "Calibrate GT Data.R" file, you can see how we calibrated the raw Google Trends data.  In the "Main Analysis and Plots" folder, you can find the data and R codes necessary to reproduce most of the analysis results and plots we presented. Check out the "README.txt" file under this folder for more information.