Where does duration collide?

The weighted-average time to receive a bond's promised payments, with each payment weighted by its present value, and, in its modified form, the resulting sensitivity of the bond's price to a small change in interest rates. Macaulay's 1938 Some Theoretical Problems Suggested by the Movements of Interest Rates, Bond Yields and Stock Prices in the United States Since 1856 introduced this weighted-average measure, now called Macaulay duration, to capture a bond's effective life better than its maturity date alone. The referent is a property of a stream of future payments, quoted in years but really a gauge of price risk, and it has nothing to do with how long a note sounds, how long a spoken vowel lasts, or how long an experience feels.[1]

Unit

A present-value-weighted time in years, or a percentage price change per unit of yield

Recovery means

Not applicable

Measured by

Computed from a bond's cash flows and yield as the present-value-weighted average of payment times, then modified to a price sensitivity

The length of time a musical tone or rest lasts, one of the basic attributes of a tone alongside pitch, loudness, and timbre; in notation it is written as relative note values, such as whole, half, and quarter notes, that are realised in real time against a chosen tempo. Seashore's 1938 Psychology of Music treated duration as the time attribute of tone, one of the measurable dimensions of every musical sound. The referent is the temporal extent of a sounded note, scaled to a beat rather than to a fixed clock, and it is distinct from a bond's price risk, the millisecond length of a speech sound, or a listener's felt passage of time.[2]

Unit

The time a note or rest is held, as a relative note value against a tempo

Recovery means

Not applicable

Measured by

Read from notated note values and tempo, or timed in seconds between a note's onset and offset in a performance

The measured length in time of a speech sound, such as a vowel or consonant, treated as an acoustic property that shifts with context and can itself tell words apart in languages that use contrastive length. Peterson and Lehiste's 1960 Duration of Syllable Nuclei in English measured how the length of stressed vowels in English depends on the surrounding consonants and identified an intrinsic length for each vowel. The referent is a physical interval of speech, read in milliseconds from a recording, and it is not a note's held length, a bond's sensitivity to interest rates, or the subjective stretch of remembered time.[3]

Unit

The time a speech segment occupies, in milliseconds

Recovery means

Not applicable

Measured by

Segmented from a spectrogram or waveform and measured in milliseconds between the onset and offset of the sound

The subjectively experienced or remembered length of an interval or episode, which can diverge sharply from its clock time; in looking back on an experience, its total length often counts for little next to its most intense moment and its ending. Fredrickson and Kahneman's 1993 Duration Neglect in Retrospective Evaluations of Affective Episodes showed that people's overall evaluation of an emotional episode barely tracked how long it lasted, a pattern they named duration neglect. The referent is a felt or judged quantity in the mind, studied through estimates and evaluations rather than a stopwatch, and it differs from a note's length, a vowel's length, or a bond's price sensitivity.[4]

Unit

A judged or estimated length of experienced time, relative to felt intensity

Recovery means

Not applicable

Measured by

Elicited through duration estimates, reproductions, or retrospective ratings and compared against actual clock time