Japan’s government is not profiting from negative yields!
1.The BOJ buys debt from the market
-> pushes prices up and yields down
-> gives extra money to the MOF.
2. The Finance Ministry pays interest income to the BOJ for the bonds it now holds
-> although rates is low (10-year notes currently at 0.1 percent)
-> the amount is huge (BOJ owns almost 327 trillion yen in sovereign debt)
-> interest income in 2015: 1.29 trillion yen
3. The BOJ then uses some of its income to pay for the valuation losses on owned bonds
<- Because BOJ buys debt for more than the face value, and has to write it down 
-> BOJ wrote down the value of JGB holding by 874 billion yen in 2015, 40% of the interest income
-> Obviously, if the amortization losses from the BOJ’s bond buying operations become too large, income could go less, even negative
-> The BOJ will buy 120 trillion yen worth of bonds this year(80 QE+40 Redemptions) 
-> if it buys 100 yen bonds at 103 yen, that would mean a total loss of 3.6 trillion yen
-> if we assume the average period is 10 year, that would mean 0.36 trillion loss increased per year ! 
-> BOJ’s last year coupon income is about 1.3 trillion, it will take only 4 years to make it negative under recent price level.
-> And don’t forget with prices high and coupons low, more and more of the debt on its books will have a negligible income and a high price that needs to be written down.
-> Therefore BOJ could go bankruptcy if bond purchasing continues! 
# but of course BOJ can prolong the duration of its holdings
4. BOJ then returns much of its leftover profits to the MOF as dividend.
5. BOJ has to cut dividend so that it could back up its reserve
-> In 2015, the BOJ cut 450 billion yen from its dividend to the government so it could increase its reserve to cover potential losses on bond holdings. 
-> According to Bloomberg, Japanese Government benefited 110 billion yen extra money from NIRP 
-> The government’s revenue actually decreased under massive stimulus!!
6. Things might be going to worse
The BOJ has approximately 2.7 trillion yen in provisions for potential bond losses after setting aside 450 billion yen in 2015, given its financial statement
If the BOJ tapers stimulus, it will face potential losses on
- bond holdings
- higher interest payments on lenders’ reserves
“When people realize the limits to the BOJ’s finances, it could possibly create a massive shock”
“The bank has about 7 trillion yen in capital, but that would be eaten up quickly.”
A. If BOJ continues its recent project, both the government and BOJ will lose money and go bankruptcy
B. If BOJ suddenly exits from its unprecedented easing policy, existing reserves will be insufficient and it will go bankruptcy
C. The BOJ have to exit, or do helicopter money. But it will definitely avoid selling its bond holdings, and “instead will probably try to maintain its balance sheet by raising the deposit rate”
So that the book value eventually equals the principal. The basic point is that as BOJ committed to hold these bonds until maturity, it doesn’t value the bonds at market price but takes the markdown gradually so that at maturity the book value equals the principal.
More specifically, for the most recent 10-year note, the MOF initially auctioned it for 101.96 yen and the BOJ probably paid more than that. It will now have to take a 2 yen or more loss on each of the bonds in that series it owns, so that when it matures in 2026, the price on its balance sheet will be back at 100 yen. The benchmark bond price was 101.779 yen, with a yield of minus 0.08 percent
In its purchase operations on June 10, the BOJ bought 416 billion yen worth of the No. 342 10-year bond, at an average price of about 102.65 yen.
The BOJ will earn 416 million yen income annually from the 0.1 percent coupon on these bonds, and will have to write down 1.1 billion yen each year to account for the 2.65 yen by which the purchase price exceeded the principal.
And don’t forget BOJ’s purchases often occur at a slight premium to the current market price.
“The BOJ couldn’t go bankrupt in the way a private bank could”
“One could make an economic case that the balance sheet of the central bank should be of marginal relevance at best to the determination of monetary policy,” Bernanke said in the speech, made years before he enacted unprecedented stimulus as Fed chair. “There are many essentially cost-less ways to fix” it, including assistance from the Ministry of Finance, he said.
Japan’s Ministry of Finance made about 110 billion yen ($1.1 billion) more in the year to April than it would have if yields had been zero
The central bank is holding on to as much as half of the profits from the interest received on its bond holdings, after an accounting rule change in November.