Legislatures vary in their capacity for detailed design and scrutiny of draft bills and oversight of the bureaucracy as a function of their formal powers and their endowment of tangible resources for legislative work. These resource endowments, such as member salaries, budgets for legislative staff, and session days, have been shown to be powerful predictors of interbranch interactions and legislative outcomes, but applied research is almost entirely limited to the study of (subnational) state governments in the US. We present new data on these resources for the national legislatures of OECD member states for the last several decades, documenting remarkable variability across units, as well as within-units over time. This variation in resource endowments presents substantial opportunity for new research in comparative political economy.