Moreover, the budgetary implications of this proposal would be essentially zero, since any increase in interest payments to the BOJ by the MOF arising from the bond conversion would be offset by an almost equal increase in the BOJ's payouts to 6 the national treasury.
The budgetary neutrality of the proposal is of course a consequence of the fact that, as a matter of arithmetic, any capital gains or losses in the value of government securities held by the BOJ are precisely offset by opposite changes in the net worth of the issuer of those securities, the government treasury.