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3: bayesian inference

Below, I extend the exploration of tokenized ecosystems by incorporating Bayesian inference into the models previously discussed, such as the AbundanceCoin ICO, Tokenized Economy, and TokenAffiliates program. Bayesian methods allow us to update our beliefs about parameters (e.g., bonding curve slopes, commission rates, or volatility) based on observed data, providing a probabilistic framework for decision-making under uncertainty. Each section is self-contained, redefines all variables and contexts, and includes numerous equations as requested, focusing on Bayesian updates rather than repeating prior stochastic models. Bayesian Inference in Tokenized Ecosystems In tokenized ecosystems, parameters governing token prices, exchange rates, and affiliate earnings are often uncertain and must be inferred from noisy data (e.g., transaction histories or market observations). Bayesian inference offers a systematic approach to estimate these parameters by combining prior knowledge with observed evidence. This paper applies Bayesian methods to refine the AbundanceCoin ICO bonding curve, predict exchange rates in a Tokenized Economy, and optimize commission rates in the TokenAffiliates program. 11. Bayesian Estimation of AbundanceCoin Bonding Curve Parameters Problem Statement: Consider the AbundanceCoin token launched via an Initial Coin Offering (ICO), where the price $ P(S) $

follows a linear bonding curve: $$ P(S) = m S + b $$

$ S $

is the circulating supply of AbundanceCoin. $ m $

is the slope, representing the price increase per unit of supply. $ b $

is the base price when supply is zero. Suppose we observe noisy price data $ D = { (S_1, P_1), (S_2, P_2), \ldots, (S_n, P_n) } $

, where $ P_i = m S_i + b + \epsilon_i $

, and $ \epsilon_i \sim N(0, \sigma^2) $

is Gaussian noise with known variance $ \sigma^2 $

. We aim to estimate $ m $

and $ b $

using Bayesian inference with prior distributions: $$ m \sim N(\mu_m, \sigma_m^2) $$

$$ b \sim N(\mu_b, \sigma_b^2) $$

Determine: a) The posterior distribution of $ m $

and $ b $

given the data $ D $

. b) The predictive distribution for the price at a new supply $ S_{\text{new}} $

. Solution: a) Posterior Distribution: The likelihood of the data given parameters m and b is:

$$ P(D | m, b) = \prod_{i=1}^n \frac{1}{\sqrt{2\pi \sigma^2}} \exp\left( -\frac{(P_i - (m S_i + b))^2}{2 \sigma^2} \right) $$

Log-likelihood:

$$ \log P(D | m, b) = -\frac{n}{2} \log(2\pi \sigma^2) - \frac{1}{2 \sigma^2} \sum_{i=1}^n (P_i - m S_i - b)^2 $$

Priors:

$$ P(m) = \frac{1}{\sqrt{2\pi \sigma_m^2}} \exp\left( -\frac{(m - \mu_m)^2}{2 \sigma_m^2} \right), \quad P(b) = \frac{1}{\sqrt{2\pi \sigma_b^2}} \exp\left( -\frac{(b - \mu_b)^2}{2 \sigma_b^2} \right) $$

Posterior (proportional):

$$ P(m, b | D) \propto P(D | m, b) P(m) P(b) $$

Define \theta = [m, b]^T , observation model h(S_i) = [S_i, 1] \theta , and data vector P = [P_1, \ldots, P_n]^T . The log-posterior is quadratic in m and b , indicating a Gaussian posterior:

$$ P(m, b | D) \sim N(\mu_{\text{post}}, \Sigma_{\text{post}}) $$

Precision matrices: Prior covariance $$ \Sigma_{\text{prior}} = \text{diag}(\sigma_m^2, \sigma_b^2) $$

, noise variance $ \sigma^2 $

. Update equations: $$ \Sigma_{\text{post}}^{-1} = \Sigma_{\text{prior}}^{-1} + \frac{1}{\sigma^2} \sum_{i=1}^n h(S_i)^T h(S_i) = \begin{bmatrix} 1/\sigma_m^2 + n/\sigma^2 & 0 \ 0 & 1/\sigma_b^2 + \sum S_i^2 / \sigma^2 \end{bmatrix} $$

$$ \mu_{\text{post}} = \Sigma_{\text{post}} \left( \Sigma_{\text{prior}}^{-1} \mu_{\text{prior}} + \frac{1}{\sigma^2} \sum_{i=1}^n h(S_i)^T P_i \right) $$

Compute numerically with data. a) Posterior Distribution: b) Predictive Distribution: For S_{\text{new}} , $$ P(S_{\text{new}}) = m S_{\text{new}} + b + \epsilon $$

, where $ \epsilon \sim N(0, \sigma^2) $

. The predictive mean and variance are:

$$ \mathbb{E}[P(S_{\text{new}})] = \mu_{\text{post}}^T [S_{\text{new}}, 1]^T $$

$$ \text{Var}[P(S_{\text{new}})] = [S_{\text{new}}, 1] \Sigma_{\text{post}} [S_{\text{new}}, 1]^T + \sigma^2 $$

  1. Bayesian Prediction of Exchange Rates in a Tokenized Economy Problem Statement: In a tokenized economy with two tokens, Token A and Token B, prices follow bonding curves: $$ P_A(S_A) = m_A S_A + b_A $$

, where S_A is Token A's supply, m_A is the slope, and b_A is the base price. $$ P_B(S_B) = m_B S_B + b_B $$

, with similar definitions for $ S_B $

, $ m_B $

, and $ b_B $

. The exchange rate is $$ R = \frac{P_A(S_A)}{P_B(S_B)} $$

. We observe noisy exchange rate data $ D = { R_1, R_2, \ldots, R_n } $

at known supplies $ (S_{A1}, S_{B1}), \ldots, (S_{An}, S_{Bn}) $

, where $ R_i = \frac{m_A S_{Ai} + b_A}{m_B S_{Bi} + b_B} + \eta_i $

, and $ \eta_i \sim N(0, \tau^2) $

is noise. Assume priors: $$ m_A \sim N(\mu_{mA}, \sigma_{mA}^2) $$

, $$ b_A \sim N(\mu_{bA}, \sigma_{bA}^2) $$

$$ m_B \sim N(\mu_{mB}, \sigma_{mB}^2) $$

, $$ b_B \sim N(\mu_{bB}, \sigma_{bB}^2) $$

Determine: a) The posterior distribution of $ m_A, b_A, m_B, b_B $

given $ D $

. b) The posterior predictive exchange rate for new supplies $ S_{A,\text{new}}, S_{B,\text{new}} $

. Solution: a) Posterior Distribution: Likelihood:

$$ P(D | m_A, b_A, m_B, b_B) = \prod_{i=1}^n \frac{1}{\sqrt{2\pi \tau^2}} \exp\left( -\frac{(R_i - \frac{m_A S_{Ai} + b_A}{m_B S_{Bi} + b_B})^2}{2 \tau^2} \right) $$

This is non-linear in parameters, so approximate with a linearized model or use Markov Chain Monte Carlo (MCMC). For simplicity, assume independence and linearize around prior means, leading to a Gaussian posterior via conjugate updates (numerical computation required). b) Posterior Predictive:

$$ R_{\text{new}} = \frac{m_A S_{A,\text{new}} + b_A}{m_B S_{B,\text{new}} + b_B} + \eta $$

Sample $ m_A, b_A, m_B, b_B $

from the posterior and compute:

$$ \mathbb{E}[R_{\text{new}}] \approx \frac{1}{K} \sum_{k=1}^K \frac{m_A^{(k)} S_{A,\text{new}} + b_A^{(k)}}{m_B^{(k)} S_{B,\text{new}} + b_B^{(k)}} $$

Variance via simulation. 13. Bayesian Optimization of TokenAffiliates Commission Rates Problem Statement: In the TokenAffiliates program, affiliates earn a commission $$ C = \alpha I $$

per investment I in AbundanceCoin, where $ I \sim \text{Exp}(\lambda) $

(exponential distribution), and $ \alpha $

is the commission rate. The platform observes total investments $ D = { I_1, I_2, \ldots, I_n } $

at a current rate $ \alpha_0 $

, aiming to infer the investment rate parameter $ \lambda(\alpha) $

, assumed linear: $$ \lambda(\alpha) = k \alpha + l $$

. Priors: $$ k \sim N(\mu_k, \sigma_k^2) $$

$$ l \sim N(\mu_l, \sigma_l^2) $$

Determine: a) The posterior distribution of $ k $

and $ l $

given $ D $

. b) The optimal $ \alpha $

maximizing expected affiliate earnings $ \mathbb{E}[C] = \alpha / \lambda(\alpha) $

. Solution: a) Posterior Distribution: Likelihood:

$$ P(D | k, l) = \prod_{i=1}^n (k \alpha_0 + l) e^{-(k \alpha_0 + l) I_i} $$

Log-likelihood:

$$ \log P(D | k, l) = n \log(k \alpha_0 + l) - (k \alpha_0 + l) \sum_{i=1}^n I_i $$

Posterior:

$$ P(k, l | D) \propto P(D | k, l) P(k) P(l) $$

Use MCMC for non-conjugate case. b) Optimal \alpha : Expected commission:

$$ \mathbb{E}[C] = \frac{\alpha}{k \alpha + l} $$

Maximize:

$$ \frac{d}{d\alpha} \left( \frac{\alpha}{k \alpha + l} \right) = \frac{l}{(k \alpha + l)^2} = 0 $$

No finite maximum; use posterior samples to balance earnings and investment volume. These Bayesian models refine parameter estimates and predictions, enhancing decision-making in tokenized systems. MCMC or numerical methods are recommended for practical implementation. Let me know if you'd like code snippets or deeper derivations!