Where does stickiness collide?

In macroeconomics, stickiness is the tendency of prices and wages to adjust slowly to changes in demand or money, so that markets do not clear at once. John Maynard Keynes named the idea in his 1936 The General Theory of Employment, Interest and Money, arguing that money wages resist downward movement and that this rigidity helps explain involuntary unemployment. Calvo's 1983 Staggered prices in a utility-maximizing framework gave the modern formal version, in which each firm may reset its price only when it draws a random chance to do so, making the average price level slow to move. The referent here is a rate of nominal adjustment in an economy, not a force between surfaces, a boundary in a random process, or the cost of moving know-how between people.[1][2]

Unit

A rate of nominal adjustment, such as the average time a price stays fixed

Recovery means

Not applicable

Measured by

Estimated from the frequency of price and wage changes in micro data, or fitted inside macroeconomic models

In probability theory, stickiness describes a diffusing particle that, on reaching a boundary, neither bounces straight back nor is absorbed but clings to it, spending a positive amount of time stuck there before moving on. William Feller's 1952 The parabolic differential equations and the associated semi-groups of transformations classified the possible behaviours of a diffusion at a boundary, and the case now called a sticky boundary comes from that classification, later realised as sticky Brownian motion. The referent is a mathematical property of a random process at a boundary, described by the equations that govern it, and it has nothing to do with slow price adjustment, the grip of an adhesive, or hard-to-move knowledge.[3]

Unit

A boundary condition on a diffusion, set by a parameter for how strongly the process sticks

Recovery means

Not applicable

Measured by

Characterised through the generator of the process and its boundary parameter

In materials and adhesion science, stickiness, usually called tack, is the ability of a material to form a bond to a surface on brief, light contact, the quality that lets a pressure-sensitive tape grab at a touch. Dahlquist set the founding rule for it in his 1969 chapter Pressure-sensitive adhesives, the criterion that a material feels tacky only when its elastic modulus stays below about a third of a megapascal at ordinary contact speeds, so it can flow into contact under a light press. Zosel's 1985 Adhesion and tack of polymers measured how tack depends on a polymer's mechanical response and surface energy. The referent is a contact-adhesion property of a physical material, not a rate of price adjustment, a random process at a boundary, or the difficulty of transferring knowledge.[4][5]

Unit

A contact-adhesion property, reported as the force or energy to separate after brief contact

Recovery means

Not applicable

Measured by

Measured by probe-tack, loop-tack, or rolling-ball tests recording peak force or debonding energy

In the study of innovation and knowledge management, stickiness is the cost and difficulty of moving a piece of information or know-how from where it sits to where it is needed. Eric von Hippel coined the term in his 1994 Sticky information and the locus of problem solving, defining sticky information as information that is costly to transfer, so that problem solving tends to happen wherever the needed information already resides. Szulanski's 1996 Exploring internal stickiness traced how such friction blocks the transfer of best practice even within a single firm. The referent is a property of knowledge and its transfer between people, not the slow movement of prices, a physical bond between surfaces, or a random process resting at a boundary.[6][7]

Unit

The cost of transferring one unit of information to a new location

Recovery means

Not applicable

Measured by

Assessed by the effort or resources a transfer takes, often via survey scales of transfer difficulty