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@@ -12,8 +12,15 @@ title: Modeling Bid Prices Under Intrinsic Cost Uncertainty
---
# Modeling Bid Prices Under Intrinsic Cost Uncertainty
The cost of a construction project is inherently uncertain until it is completed,
therefore the most accurate model of cost is a distribution of possible costs.
Customers request bids as a single cost, however,
so a contractor must determine some function
to convert from the true cost model to a single bid price.
> [!warning]
> This text is almost entirely LLM output.
> From this point forward,
> this text is almost entirely LLM output.
> I don't intend to keep or use any significant portions of it.
Consider a construction project characterized by an intrinsic but unknown final cost $C$.
@@ -28,9 +35,12 @@ $$
C : \Omega \to [0,\infty)
$$
> Read as
> "C is a function from omega to the interval from zero to infinity, including zero."
with [distribution](https://en.wikipedia.org/wiki/Probability_distribution) $\mu_C$.
The distribution $\mu_C$ summarizes all available information at the time of bidding,
The distribution $\mu_C$ accounts all available information at the time of bid,
including quantities, labor productivity uncertainty,
market conditions, subcontractor pricing variability,
and correlation structures inherent to the estimator's assumptions.
@@ -59,7 +69,7 @@ mapping a cost distribution $\mu_C$ to a **scalar** (a single value).
Examples of such functionals include:
### 1. Risk-neutral expectation
## 1. Risk-neutral expectation
$$
\Phi(\mu_C) = \mathbb{E}[C],
@@ -69,7 +79,7 @@ $$
where $\mathbb{E}[\cdot]$ denotes the [expected value](https://en.wikipedia.org/wiki/Expected_value).
### 2. Risk-adjusted expectation
## 2. Risk-adjusted expectation
$$
\Phi(\mu_C) = \mathbb{E}[C] + \lambda\sqrt{\mathrm{Var}[C]},
@@ -80,9 +90,9 @@ $$
where $\mathrm{Var}[C]$ is the [variance](https://en.wikipedia.org/wiki/Variance)
and $\lambda>0$ is a risk-loading parameter.
> This mirrors mean--variance pricing common in portfolio theory.
> This mirrors mean-variance pricing common in portfolio theory.
### 3. Quantile-based pricing
## 3. Quantile-based pricing
$$
\Phi(\mu_C) = Q_p(C),
@@ -93,7 +103,7 @@ $$
where $Q_p$ is the $p$-[quantile](https://en.wikipedia.org/wiki/Quantile)
of the distribution.
### 4. Utility-maximizing bid
## 4. Utility-maximizing bid
Under a bidder [utility](https://en.wikipedia.org/wiki/Utility) function $U$,
@@ -106,7 +116,7 @@ $$
> [$\arg\max$](https://en.wikipedia.org/wiki/Arg_max) is the value of $b$ that maximizes the expression.
***
## Conclusion
The central tension is: