Where does demand collide?

The quantity of a good that buyers are willing and able to purchase at each possible price, traced as a schedule or curve that slopes downward as price falls. Marshall's 1890 Principles of Economics set out the demand schedule and the curve relating price to quantity demanded, along with the elasticity that describes how sharply the quantity responds. The referent is a relation between price and the amount bought in a market, estimated from prices and quantities, and it is not the workload a job imposes, a cue that tells a participant what a study wants, a party's formal legal claim, or the electrical load drawn from a supply.[1]

Unit

The quantity buyers will purchase at a given price, read along a demand curve

Recovery means

Not applicable

Measured by

Estimated by fitting a demand curve to price and quantity data, and summarised by its price elasticity

The physical, psychological, social, or organizational features of a job that require sustained physical or mental effort and are therefore associated with physiological and psychological costs. Bakker and Demerouti's 2007 The Job Demands-Resources model: State of the art set job demands opposite job resources, arguing that demands drive a health-impairment path toward strain and burnout while resources drive a motivational path toward engagement. The referent is a source of effort and cost inside a job, rated on a self-report scale, and it has nothing to do with a market quantity, a participant's inferred cue, a party's legal claim, or a circuit's power draw.[2]

Unit

The effortful pressures of a job, rated on a job demands questionnaire

Recovery means

Job resources and recovery periods buffer the strain that sustained demands produce

Measured by

Assessed by self-report scales covering workload, time pressure, and emotional demands

The totality of cues within a study that convey the experimenter's hypothesis to a participant and lead the participant to guess its purpose and act on that guess. Orne's 1962 On the social psychology of the psychological experiment named these demand characteristics and showed how they can shape results independently of the manipulation under test. The referent is the set of situational hints that betray a study's aim, probed after the fact, and it is unrelated to the quantity buyers will purchase, the pressures of a job, a formal legal demand, or peak electrical load.[3]

Unit

The cues that signal a study's aim to its participants

Recovery means

Not applicable

Measured by

Probed by post-experimental inquiry, quasi-control groups, and checks on what participants inferred

The electrical load a system draws from its supply, averaged over a specified interval such as fifteen or thirty minutes, with peak or maximum demand being the highest such value over a period. Willis's 2004 Power Distribution Planning Reference Book treats demand as the averaged load that sizes equipment and drives billing, distinct from the instantaneous power at any single moment. The referent is power drawn over a demand interval, metered in kilowatts or kilovolt-amperes, and it shares nothing but the word with a market quantity, a job's pressures, a study's cues, or a legal claim.[4]

Unit

Power drawn over a demand interval, in kilowatts or kilovolt-amperes

Recovery means

Not applicable

Measured by

Metered as the load averaged over a demand interval, with the highest reading recorded as peak demand