The massive amount of text provided by users of social media like Facebook and Twitter give researchers the opportunity to investigate topics that were not previously tangible.
then, we perform randomized principal components analysis (RPCA) , an approximate PCA based on stochastic re-sampling (Rokhlin et al., 2009)  We learn four different models: (1) a control model using the socioeconomic & demographic variables, (2) a language model using only tweetderived features, (3) a combined model using both socioeconomics & demographics and language in a single model, and (4) a language over residualized control model fitting language to the residual error of the control model.