ineconomy n.

word-forming element meaning "not, opposite of, without" (also im-, il-, ir- by assimilation of -n- with following consonant, a tendency which began in later Latin), from Latin in- "not," cognate with Greek an-, Old English un-, all from PIE root *ne- "not."

In Old French and Middle English often en-, but most of these forms have not survived in Modern English, and the few that do (enemy, for instance) no longer are felt as negative. The rule of thumb in English has been to use in- with obviously Latin elements, un- with native or nativized ones.

1530s, "household management," from Latin oeconomia (source of French économie, Spanish economia, German Ökonomie, etc.), from Greek oikonomia "household management, thrift," from oikonomos "manager, steward," from oikos "house, abode, dwelling" (cognate with Latin vicus "district," vicinus "near;" Old English wic "dwelling, village," from PIE root *weik- (1) "clan") + nomos "managing," from nemein "manage" (from PIE root *nem- "assign, allot; take").

The meaning "frugality, judicious use of resources" is from 1660s. The sense of "wealth and resources of a country" (short for political economy) is attested from 1650s, but even in the 1780s the American Founders in laying out the new republic generally used economy only as "frugality." So also in that sense in the Federalist, except in one place where full political economy is used.

Col Mason — He had moved without success for a power to make sumptuary regulations. He had not yet lost sight of his object. After descanting on the extravagance of our manners, the excessive consumption of foreign superfluities, and the necessity of restricting it, as well with oeconomical as republican views, he moved that a Committee be appointed to report articles of Association for encouraging by the advice the influence and the example of the members of the Convention, oeconomy[,] frugality[,] and american manufactures. [Madison, Sept. 13, 1787, in Farrand, "Records of the Federal Convention;" the motion was agreed to without opposition]