Rates tighten
----------------------
Economists frequently study quantitative variables such as quantities produced or consumed, prices, and so on. These various quantities are quite often expressed in relative terms—that is, as percentages. They may then be expressed as elasticities or rates.
The Latin verb taxare took on various meanings over time: at first it meant "to blame," then "to assess," and finally "to tax." In Old French, it subsequently gave rise to the verb tausser, also spelled tauxer, from which the noun taux was derived. During the Renaissance, this noun meant a tax or levy; much later, it also came to denote a proportion or percentage.
For economists and managers, a rate may denote a price fixed by law or custom. This is the case with an exchange rate, which is the price of one currency expressed in terms of a foreign currency. But the same word may also refer to a percentage.
