South Korea 12-Month KORIBOR

KRKORIBOR12M is the raw twelve-month Korea Interbank Offered Rate recorded without any transformation, namely the quoted annualized reference rate for unsecured interbank term lending at the twelve-month tenor. As a yield it follows the yield-to-maturity convention that maps a fixed-maturity claim's price to its single terminal cash flow, a construct that originates in the measurement of bond yields over time and was later generalized to the full term structure of zero-coupon rates (Macaulay 1938; Fisher and Weil 1971).

The twelve-month tenor places this quote within the short end of the interest-rate term structure, a segment whose decomposition into expected future short rates plus a liquidity premium was first defined and later made operational as a smooth function recoverable from market prices (Hicks 1939; McCulloch 1971, 1975; Vasicek and Fong 1982; Nelson and Siegel 1987; Svensson 1994). A quote of this kind anchors the short end of the daily fitted curve produced by the off-the-run curve-fitting practice evaluated across competing estimators (Gürkaynak, Sack, and Wright 2007; Bliss 1997).

The interbank offered rate is a term unsecured claim distinct from secured collateralized financing, which carries its own specialness, and from the overnight unsecured call rate from which it differs by tenor rather than by counterparty type (Duffie 1996; Hamilton 1996; Furfine 1999). Its level is anchored, like other short-dated money-market rates, by policy operations that steer the front end of the curve toward a central operating target inside a standing-facility corridor, an arrangement that varies in form across operating procedures (Borio 1997; Bindseil 2004; Bartolini, Bertola, and Prati 2002).

KRED applies no transformation to the quoted twelve-month Korea Interbank Offered Rate and stores it exactly as observed, so the methodology is limited to the measurement basis by which such a term interbank benchmark rate comes to exist, performing no rescaling, deflating, smoothing, or annualizing.

A twelve-month money-market quote is a point estimate of the term structure at that maturity. Its smooth recovery from market prices developed through the cubic-spline discount function, its tax-adjusted refinement, the exponential-spline method, and the parsimonious level-slope-curvature form and its extension (McCulloch 1971, 1975; Vasicek and Fong 1982; Nelson and Siegel 1987; Svensson 1994). The operational daily procedure of reading par, zero, and forward rates of any maturity from smoothed off-the-run prices follows established curve-fitting practice, and competing estimators over short maturities have been shown to deliver closely comparable results (Gürkaynak, Sack, and Wright 2007; Bliss 1997). The underlying yield-to-maturity basis, whereby a fixed-maturity instrument's price implies a single annualized discount rate, was formalized before being generalized to the zero-coupon term structure and to duration-based immunization (Macaulay 1938; Fisher and Weil 1971).

Because the interbank offered rate is an unsecured term claim rather than secured repo financing, its quoted level is read against the secured-rate benchmark and the overnight unsecured measurement, and its position within the operating-target framework follows the same implementation literature that governs other short-dated policy-transmission rates (Duffie 1996; Hamilton 1996; Furfine 1999; Borio 1997; Bindseil 2004; Bartolini, Bertola, and Prati 2002). KRED performs none of these estimation steps and records only the already-quoted figure, with no seasonal adjustment applied, consistent with the series carrying no seasonal structure.

The twelve-month Korea Interbank Offered Rate is a money-market price through which the monetary-policy operating target is transmitted to term interbank borrowing costs. The operating-procedure framework defines how an operating-target rate is pinned by open-market operations and standing facilities (Borio 1997; Bindseil 2004), and the mechanism by which day-to-day operations steer short rates around that target has been modeled separately (Bartolini, Bertola, and Prati 2002).

Because this quote sits at the twelve-month point on the term structure, its level separates expected future short rates from term and liquidity premia under the forward-rate and liquidity-premium decomposition (Hicks 1939), a reading sharpened by term-structure measurement across parsimonious and spline-based estimators (McCulloch 1971; Nelson and Siegel 1987; Svensson 1994; Gürkaynak, Sack, and Wright 2007).

The spread of this unsecured interbank term rate over the secured collateralized rate and over the overnight unsecured call rate is informative about interbank funding conditions and counterparty risk (Duffie 1996; Hamilton 1996; Furfine 1999). The duration sensitivity of any claim priced off this rate follows the yield-to-maturity and duration methods first developed for bond markets (Macaulay 1938; Fisher and Weil 1971).

As a term money-market reference rate, the twelve-month Korea Interbank Offered Rate is embedded as the index against which floating-rate loans reset at the twelve-month tenor. Claims that reset off it are priced and hedged using the yield-to-maturity and duration machinery developed for money-market and bond instruments (Macaulay 1938; Fisher and Weil 1971).

Discounting and curve construction for such instruments place this quote on the zero-coupon curve, recovered from market prices through cubic-spline, exponential-spline, and parsimonious parameterizations (McCulloch 1971, 1975; Vasicek and Fong 1982; Nelson and Siegel 1987; Svensson 1994), with the short-maturity point fitted per the daily off-the-run construction and estimator comparison (Gürkaynak, Sack, and Wright 2007; Bliss 1997).

Relative-value and funding desks read this interbank term rate against the secured repo benchmark and the overnight unsecured call rate (Duffie 1996; Hamilton 1996; Furfine 1999), and its level relative to the policy operating target follows the implementation frameworks that govern the front end of the curve (Borio 1997; Bindseil 2004; Bartolini, Bertola, and Prati 2002). The front-end curve built around this quote implies the expected path of short rates priced by the market, whose forward-rate content was first identified in the classic decomposition (Hicks 1939).

On the 5,452 daily observations spanning 2004-07-26 to 2026-07-24, fit with a constant and trend, the unit-root battery agrees that the twelve-month Korea Interbank Offered Rate is integrated of order one. The augmented Dickey-Fuller test of Dickey and Fuller (1979), in the ARMA-consistent lag-augmented form of Said and Dickey (1984) and with lag length set as in Ng and Perron (2001), does not reject a unit root with p = 0.4797, the nonparametric Phillips and Perron (1988) test concurs with p = 0.8186, and the Kwiatkowski et al. (1992) stationarity test rejects its trend-stationary null at p < 0.01, so the verdict is an unambiguous I(1). The GLS-detrended power escalation of Elliott, Rothenberg, and Stock (1996) is reserved for ambiguous outcomes under the house protocol and is not required on this clean reading.

Because the level is integrated, the mean-shift and serial-correlation diagnostics are run on the first difference, the stationary object those procedures require, since a break search or a portmanteau on an integrated level would spuriously segment and read near-unit autocorrelations (Bai and Perron 1998; Perron 1989). The multiple-break procedure of Bai and Perron (1998), computed by the dynamic-programming algorithm of Bai and Perron (2003), finds 3 breaks in the mean of the differenced series, at 2008-10-23, 2019-08-08, 2022-11-25, read as parameter instability in the sense of Andrews (1993). The Ljung and Box (1978) portmanteau statistic, refining the original Box and Pierce (1970) form, is computed on the first difference and rejects the white-noise null at lags 10 and 20, with Q = 3291.24 and Q = 4437.76 and p = 0.000 and p = 0.000, and the automatic portmanteau test of Escanciano and Lobato (2009) concurs with a statistic of 425.17 at p = 0.000.

The series is daily and has no low-integer seasonal period, so the seasonal-unit-root machinery of Hylleberg et al. (1990) and the Canova and Hansen (1995) seasonal-stationarity test are inapplicable and are deliberately not run, the degeneracy of the seasonal auxiliary regression at a daily period being the standard ground (Beaulieu and Miron 1992; Ghysels and Osborn 2001).