Dataset properties:

• Measurements: Percent per annum (% p.a.), percentage (%), unitary count (#), or millions of euros (Mil. EUR)
• Adjustment: Not seasonally adjusted (NSA)
• Native frequency: Business daily (Monday to Friday)
• Start date: 15 March 2017

The series reside in the historical catalog (Euro Zone » Financial » Interest Rates » Daily » ESTER) and include, for example:

• IR%ESTERUD.IEUZN    = Interest rates: Euro short-term rate [pre-ESTER] - Volume-weighted trimmed mean, (% p.a., NSA)
• IR%ESTERP25UD.IEUZN = Rate at 25th percentile of volumes, (% p.a., NSA)
• IRLESTERTNUD.IEUZN  = Total turnover, (Mil. EUR, NSA)
• IRQESTERBKUD.IEUZN  = Banks, (#, NSA)

Because catalog locations are subject to change, the upper-right search box on DataBuffet.com provides a "find in catalog" mode that accepts a mnemonic.

About the dataset

In the wake of the BBA LIBOR scandal and Wheatley Review (2012), the International Organisation of Securities Commissions (IOSCO) published Principles for Financial Benchmarks (2013), which have been transformed into European law (EU 2016/1011 and EU 2017/1147). The established interest rate benchmarks LIBOR, EURIBOR and EONIA are not compliant. To fill the function of reference rate, new entities called risk-free rates (RFRs) are being developed as successors to interbank rates (IBORs). EURIBOR is being reformed; concurrently, the European Central Bank (ECB) has been developing the euro short-term rate (ESTER), which is intended as an EONIA successor by 2020. ESTER is derived from daily money market reporting by the 52 largest euro area banks, who conduct euro uncollateralized (or unsecured) overnight loans.

Until October 2019 the program is in a testing phase ("pre-ESTER"), during which ECB will calculate and publish figures so that entities may determine the usability of the rates.

The source explains the test program (citation):

Pre-ESTER is calculated using the same methods as defined for ESTER. Pre-ESTER differs in that it is based on final data and includes all revisions in terms of cancellations, corrections and amendments submitted by reporting agents at the time of calculating the rate, while ESTER will be published every morning and take into account only the data received by the submission deadline of 07:00 CET that morning.

References

At the source:

• Pre-ESTER (pdf)
• Euro short-term rate (ESTER)
• ESTER methodology and policies (pdf)

Third-party commentary, etc.:

• Principles for financial benchmarks - Final report (IOSCO, Jul 2013, pdf)
• A tale of two benchmarks: The future of euro interest rates (Oliver Wyman, Jun 2018)
• Benchmark reform - An EONIA replacement is coming very soon! (Clarus Financial Technology, Jun 2018)
• Reform of interest rate benchmarks (Financier Worldwide, Jul 2018)