RATES

A rate is a measure of the frequency of an event or phenomenon. In public health, vital statistics, epidemiology, and other aspects of the health sciences and health care, events of interest include birth, deaths (so-called vital events), outbreaks of disease, spells of sickness, hospitalizations, immunizations against infectious diseases, and many other events and phenomena. A rate is more than a number: Its aim is to compare frequencies of phenomena at different times and places, among different classes of persons. Rates are calculated by a simple arithmetical procedure:

The components of a rate are the numerator (the number of events), the denominator (the population at risk of experiencing the event), the specified period in which the events occurred, and a multiplier (a power of 10) that converts the rate from an awkward fraction to a whole number. All rates are ratios; some rates are proportions (the numerator is a portion of the denominator). For example, the "case fatality rate" is the number of fatal cases as a proportion of all cases of a condition, such as hospitalized patients with acute heart attacks. Sometimes the meaning is further restricted to mean change over time or, alternatively, the cases of a disease originating at an instant in time, known as the "instantaneous incidence rate." The customary usage refers to the ratio of cases to the population at risk of experiencing the event over a period of time, usually a year. Since the size of the population may fluctuate over this period, the denominator for this rate is arbitrarily selected to be the population midway through the year.

John M. Last

(see also: Incidence and Prevalence; Population at Risk; Rates: Adjusted; Rates: Age-Adjusted; Rates: Age-Specific )

rates are taxes on the occupiers of land and buildings. Various Acts in the 16th cent. provided for a poor rate for the relief of the sick and destitute, but in England ‘the rates’ date back formally to the Poor Relief Act of 1601, which made the parish the administrative unit for rating and gave ‘overseers’ (churchwardens and substantial householders) the power to tax. In 1647 an ordinance consolidated the church rate with the poor rate. As local authorities provided new services, additional rates were levied.

The Rating and Valuation Act (1925) brought in the general rate and made county boroughs, boroughs, etc. the rating authorities (in place of the overseer) and the units of rating (in place of the parish). The rates were unpopular because they were mildly regressive and paid by only part of a local electorate. In the 1970s and 1980s various investigations, the Layfield Report (Local Government Finance, 1976) and two Green Papers (‘Alternatives to Domestic Rates’, 1981, and ‘Paying for Local Government’, 1986) set out alternative local taxes. Domestic rates, but not business rates, were abolished in 1989–93, in Scotland, and in 1990–3, in England and Wales, when they were replaced by the community charge or poll tax.

Margaret Wilkinson