MUDA

%matplotlib inline
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
import networkx as nx
import pymarket as pm

Creates new market

r = np.random.RandomState(1234)
mar = pm.Market()

mar.accept_bid(1, 6.7, 0, True, 0)
mar.accept_bid(1, 6.6, 1, True, 0)
mar.accept_bid(1, 6.5, 2, True, 0)
mar.accept_bid(1, 6.4, 3, True, 0)
mar.accept_bid(1, 6.3, 4, True, 0)
mar.accept_bid(1, 6, 5, True, 0)

mar.accept_bid(1, 1, 6, False, 0)
mar.accept_bid(1, 2, 7, False, 0)
mar.accept_bid(2, 3, 8, False, 0)
mar.accept_bid(2, 4, 9, False, 0)
mar.accept_bid(1, 6.1, 10, False, 0)

bids = mar.bm.get_df()
transactions, extras = mar.run('muda', r=r)
stats = mar.statistics()

Orignal supply and demand curves

mar.plot()

Supply and demand curves after market is splitted

ax = mar.plot_method('muda')

Analysis of the Left Side

Participants

• Buying: 1, 3, 4
• Selling: 7, 8, 9

Trading price

• \(6.3\)

Results

• The long side is the supply, all demand side buys as much as they want
• The demand side pays no fees, they are the short side
• Bid 7, results in bid 9 not trading a unit, so the fee is $ 1 :nbsphinx-math:`times `(6.3 - 4) = 2.3$
• Bid 8, results in bid 9 not trading a 2 units so the fee is \(2 \times (6.3 - 4) = 4.6\)

Analysis of the Right Side

Participants

• Buying: 0, 2, 5
• Selling: 6, 10 (10 does not trade because bid price is greater than trading price)

Trading price

• 4.65

Results

• The long side is the demand, all supply side buys as much as they want
• The supply side pays no fees, they are the short side
• Bid 0, results in bid 2 not trading a unit, so the fee is $ 1 :nbsphinx-math:`times `(6.5 - 4.65) = 1.85$

Statistics

print('Percentage of the maximum possible traded quantity')
stats['percentage_traded']

Percentage of the maximum possible traded quantity

0.6666666666659999

print('Percentage of the maximum possible total welfare')
stats['percentage_welfare']

Percentage of the maximum possible total welfare

0.7906976744186046

print('Profits per user')
for u in bids.user.unique():
    print(f'User {u:2} obtained a profit of {stats["profits"]["player_bid"][u]:0.2f}')

Profits per user
User  0 obtained a profit of 2.05
User  1 obtained a profit of 0.30
User  2 obtained a profit of 0.00
User  3 obtained a profit of 0.10
User  4 obtained a profit of 0.00
User  5 obtained a profit of 0.00
User  6 obtained a profit of 3.65
User  7 obtained a profit of 4.30
User  8 obtained a profit of 6.60
User  9 obtained a profit of 0.00
User 10 obtained a profit of 0.00

print(f'Profit to Market Maker was {stats["profits"]["market"]:0.2f}')

Profit to Market Maker was 8.75