What precisely is the sacramental "economy"? In which sense it is an economy? I have always been puzzled by the use of the word "economy" linked to the sacraments, or in other expressions like "economy of salvation", "economy of creation", Divine "economy" (see full list of its uses in the Catechism here). As an economist, I don't see why such word is linked there. 

The definition of the sacramental economy in the Catechism is:


  1076 The Church was made manifest to the world on the day of Pentecost by the outpouring of the Holy Spirit. The gift of the Spirit ushers in a new era in the "dispensation of the mystery" the age of the Church, during which Christ manifests, makes present, and communicates his work of salvation through the liturgy of his Church, "until he comes." In this age of the Church Christ now lives and acts in and with his Church, in a new way appropriate to this new age. He acts through the sacraments in what the common Tradition of the East and the West calls "the sacramental economy"; this is the communication (or "dispensation") of the fruits of Christ's Paschal mystery in the celebration of the Church's "sacramental" liturgy.


So, the use of "economy" here seems to imply a "system" related to the "administration" of grace via sacraments, implemented through a communication between God and the faithful, mediated through a presbyter or deacon or so, and effected via a liturgical rite. How this relates to usual understandings of the word economy, I have no idea. 

Why is this word used? How is it to be understood? The Catechisms speaks about its name coming from a "common Tradition of the East and the West". Maybe a reference to this tradition could clarify the original meaning of the word economy here. 

PS: I hope this is on topic.
Oἰκονομία means "the management of a household" or "stewardship", as in the Septuagint's Is. 22:19 ("And I will…depose thee from thy ministry [οικονομίας].") or Lk. 16:2 ("give an account of thy stewardship [οἰκονομίας]: for now thou canst be steward [οἰκονομεῖν] no longer.").

The OED gives these theological definitions for "economy":


  a. The method of divine government of the world, or of a specific aspect or part of that government.The sense is used pre-eminently of God's dealings with mankind in the Incarnation, but also as these relate to creation and revelation through Scripture and the reconciling activity in the Sacraments.b. spec. A method or system of divine government suited to the needs of a particular nation or period of time, as Mosaic economy, Jewish economy, Christian economy, etc. Cf. dispensation n. 6.