Public Economics

Emmanuel Saez Undergraduate Public Economics 

Data analysis

Gábor Békés and Gábor Kézdi. Data Analysis for Business, Economics, and Policy. [Book, data & code] 

Introduction to Econometrics with R [Webpage] 

Econometric Methods (ANU course) [Webpage] 

Andrew Baker, Brantly Callaway, Scott Cunningham, Andrew Goodman-Bacon, Pedro H. C. Sant'Anna Difference-in-Differences Designs: A Practitioner's Guide  

Causal Claims in Economics 

Difference in Difference