Low Interest Rates, Part 1: Economic and Fiscal Implications [Updated February 25, 2019] [open pdf - 742KB]
From the Document: "When describing interest rate trends, each debt instrument is different. The interest rate on every debt instrument is determined by market supply and demand for that instrument, and each instrument has different characteristics, including issuer, maturity length, and liquidity. Analysts often focus on two specific interest rates to gauge overall interest rate trends--the yield on Treasuries (marketable federal debt instruments) and the federal funds rate (the overnight interbank lending rate)."
CRS Insight, IN11044
Congressional Research Service: https://crsreports.congress.gov/