What problem does it solve? Running rigorous statistical analysis in Python often means stitching together model fitting, assumption testing, and inference by hand. This Skill provides guided workflows for statsmodels so you get correct model classes, diagnostics, and publication-ready coefficient tables without memorizing the API. ## Core Features & Use Cases - Regression and GLM modeling: Fit OLS, WLS, GLS, quantile regression, logistic, Poisson, Negative Binomial, and mixed effects models with robust standard errors. - Time series analysis: Build ARIMA, SARIMAX, VAR, and state space models with stationarity tests, ACF/PACF identification, and forecasts with confidence intervals. - Diagnostics and inference: Run heteroskedasticity, autocorrelation, normality, and influence tests, plus ANOVA, multiple comparisons, and power analysis. - Use Case: Given a dataset of patient visits, fit a Negative Binomial model after detecting overdispersion in a Poisson fit, interpret rate ratios, and validate residuals before reporting. ## Quick Start Ask the AI to fit an OLS regression of your outcome on your predictors using statsmodels, including a constant term, residual diagnostics, and a full summary table.