From the 2002 General Instruction of the Roman Missal (GIRM) approved for the USA, which can be accessed from
romanrite.com/girm.html :
“
The Chair for the Priest Celebrant and Other Seats
310. The chair of the priest celebrant must signify his office of presiding over the gathering and of directing the prayer. Thus the best place for the chair is in a position facing the people at the head of the sanctuary, unless the design of the building or other circumstances impede this: for example, if the great distance would interfere with communication between the priest and the gathered assembly, or if the tabernacle is in the center behind the altar. Any appearance of a throne, however, is to be avoided.[footnote 119: Cf. Sacred Congregation of Rites, Instruction Inter Oecumenici, on the orderly carrying out of the Constitution on the Sacred Liturgy, 26 September 1964, no 92: AAS 56 (1964), p. 898] …”.
This is a little different to the 1975 GIRM: “271. The priest celebrant’s chair ought to stand as a symbol of his office of presiding over the assembly and of directing prayer. Thus the best place for the chair is at the back of the sanctuary and turned toward the congregation, unless the structure or other circumstances are an obstacle (for example, if too great a distance would interfere with communication between the priest and people). Anything resembling a throne is avoided.”
I notice the example of “if the tabernacle is in the center behind the altar” which was added in 2002. From my observations a majority of churches have this arrangement. Despite this we still have “…the best place for the chair is in a position facing the people at the head of the sanctuary, unless …”.
