Merge pull request #437 from ergoplatform/i392

Update fee and economy model

papers/yellow/economy.tex

@@ -0,0 +1,40 @@
+\section{Economic survivability}
+
+We outline following two properties required for long-term survivability of the chain:
+
+\begin{itemize}
+    \item{} Coins with lost keys should be returned into circulation.
+    Otherwise, after the end of the initial coins emission period, amount of the coins
+    in the circulation always decrease and eventually reach zero.
+    \item{} Nothing should be kept in the state forever and for free.
+    Otherwise, the size of the state is always increasing, thus reducing clients performance.
+\end{itemize}
+
+To achieve this, we propose the following modifications to the consensus rules.
+Register $R2$ of the box will contain tuple $(tx\_id, out\_num,
+last\_height)$. $last\_height$ field is used to determine the block height
+at the moment of transaction generation. Transaction can only be put in the
+block of height $h$ if for every created box $R2.last\_height < h$.
+
+Once the subsidized period for the box ends (that is,
+$current\_block\_height \ge R2.last\_height + SP$), anyone (presumably a miner) can
+create the new box with the exactly the same content (including the guarding
+script) except the monetary value and $R2$ content. The monetary value is
+reduced by $K \cdot B$, where $B$ is the box size and $K$ is the storage cost of one byte.
+Thus, $K \cdot B$ coins are to be paid to the miner.
+If box value is less that $K \cdot B$, all box content including tokens goes to miner.
+$R2.tx\_id$ and $R2.out\_num$ content of created box should contain correct transaction id
+and index, while $R2.last\_height$ should be set to $R2.last\_height$ of spending box
+plus $SP$, to ensure that subsidized period starts over.
+
+We propose the following concrete parameters:
+\begin{itemize}
+    \item{} $K$ - cost of storage of 1 byte of data in a State for 1 block.
+    Should be determined by miner votes, $10^{-6} (Ergo/byte)$ by default.
+    \item{} $SP$ - number of blocks, box can be stored in a State for free untouched.
+    Since Ergo have tokens as a first-class citizens, it might be possible that tokens value
+    sufficiently exceed Ergo value in a box, thus $SP$ should be big enough to protect users
+    that only keep tokens in their boxes.
+    However, $SP$ should not exceed emission length to reward miners.
+    It is predefined $SP = 1051200 = 4$ years.
+\end{itemize}

papers/yellow/main.tex

@@ -531,6 +531,8 @@ \subsection{Regular}
 
 \include{emission}
 
+\include{economy}
+
 \section{Transactions}
 
 
@@ -799,24 +801,6 @@ \subsection{Token Emission}
 \section{Voting}
 \input{voting.tex}
 
-\section{Transaction Fees}
-Register $R2$ of the box contains tuple $(tx\_id, out\_num,
-last\_height)$. $last\_height$ field is used to determine the block height
-at the start of the subsidized period. Transaction can only be put in the
-block of height $h$ if for every created box $R2.last\_height<h$.
-
-Transaction fees must satisfy relation $fee\ge max(K\sum_i B_i, Cd_{comp})$.
-Here $K$ is the storage cost of one byte for the subsidized period, $B_i$ is the
-size of $i$th created box. $d_{comp}$ is the amount of computations required by
-the transaction, and $C$ is the cost of unit computation.
-
-Once the subsidized period for the box ends (that is,
-$current\_block\_height\ge R2.last\_height + subsidized\_period$), anyone can
-create the new box with the exactly the same content (including the guarding
-script) except the monetary value and $last\_height$.  The monetary value is
-reduced by $KB$ where $B$ is the box size, and $KB$ coins are to be paid to
-miner. $last\_height$ is replaced with the $current\_block\_height$, so that the
-subsidized period starts over.
 
 \vnote{Script needed}