# Agentic Racing Math Audit

This audit checks the main mathematical claims in `agentic_racing.tex`.

## 1. Shifted Reliability and Boundary Value

The paper starts with a shifted reliability curve

\[
p(q,h)=G(q-h),
\qquad g=G'.
\]

Task surplus on an interval \(H\) is

\[
W(q;H)=\int_H a(h)G(q-h)dh.
\]

Differentiating under the integral sign gives

\[
W'(q;H)=\int_H a(h)g(q-h)dh
\equiv B(q;H).
\]

Thus the marginal value of capability is a kernel-weighted value density around the current task-horizon boundary.

## 2. Gompertz Reliability Case

The Poisson reliability case is

\[
p(q,h)=\exp[-\exp(h-q)].
\]

This is \(G(q-h)\) with

\[
G(s)=\exp[-\exp(-s)].
\]

The derivative is

\[
g(s)=G'(s)=\exp[-s-\exp(-s)].
\]

It integrates to one:

\[
\int_{-\infty}^{\infty}\exp[-s-\exp(-s)]ds=1.
\]

Set \(z=\exp(-s)\), so \(dz=-\exp(-s)ds\). Then the integral becomes

\[
\int_\infty^0 -e^{-z}dz
=\int_0^\infty e^{-z}dz=1.
\]

## 3. Bounded Menus Saturate

If \(H=(-\infty,\bar h]\), \(A_H=\int_H a(h)dh<\infty\), and \(g(s)\to0\) as \(s\to\infty\), then for every fixed \(h\le \bar h\),

\[
g(q-h)\to0
\quad\text{as }q\to\infty.
\]

Since \(g\) is bounded and \(a\) is integrable, dominated convergence gives

\[
B(q;H)=\int_H a(h)g(q-h)dh\to0.
\]

So fixed limited-horizon task menus cannot sustain positive marginal capability value indefinitely.

## 4. Moving Agentic Frontiers Need Not Saturate

If \(a(h)\ge a_0>0\) for \(h\in[q-w,q+w]\), then

\[
B(q;H)
\ge
a_0\int_{q-w}^{q+w}g(q-h)dh.
\]

With \(s=q-h\), this is

\[
B(q;H)
\ge
a_0\int_{-w}^{w}g(s)ds>0.
\]

Thus an expanding or unbounded task-horizon frontier can sustain positive marginal value.

## 5. Scaling-Law Derivatives

The paper uses

\[
L(C)=L_\infty+\chi(C+\kappa)^{-\eta}.
\]

Set \(y=C+\kappa\) and \(b=L_\infty/\chi\). Then

\[
L(C)=\chi y^{-\eta}(1+by^\eta)
\]

and

\[
q(C)=-\log L(C)
=-\log\chi+\eta\log y-\log(1+by^\eta).
\]

Differentiating:

\[
q'(C)=\frac{\eta}{y}-\frac{b\eta y^{\eta-1}}{1+by^\eta}
=\frac{\eta}{y(1+by^\eta)}.
\]

Differentiating again:

\[
q''(C)=
-\frac{\eta[1+(1+\eta)by^\eta]}{y^2(1+by^\eta)^2}<0.
\]

A physical training project \(\varepsilon\) gives

\[
\Delta q=q(C+e\varepsilon)-q(C)
=eq'(C)\varepsilon+O(\varepsilon^2).
\]

## 6. Temporary Lead Values

A successful frontier step has task-surplus value

\[
S(q,\Delta)=W(q+\Delta)-W(q).
\]

If the lead duration \(\tau\) is exponential with rate \(\mu\), then

\[
\mathbb E\left[\int_0^\tau e^{-rt}dt\right]
=
\int_0^\infty e^{-rt}\Pr(\tau>t)dt
=
\int_0^\infty e^{-(r+\mu)t}dt
=\frac{1}{r+\mu}.
\]

Therefore

\[
L(q,\Delta)=\frac{\pi S(q,\Delta)}{r+\mu},
\qquad
D(q,\Delta)=\frac{\beta S(q,\Delta)}{r+\mu}.
\]

The private contest prize from shifting the lead from the rival to the lab is

\[
P(q,\Delta)=L(q,\Delta)+D(q,\Delta)
=\frac{\pi+\beta}{r+\mu}S(q,\Delta).
\]

Locally,

\[
P(C,\varepsilon)
\simeq
\frac{\pi+\beta}{r+\mu}eq'(C)\varepsilon B(q).
\]

## 7. Symmetric Contest Equilibrium

Let aggregate race effort be \(X=x_i+x_j\). Completion probability is \(\Lambda(X)\), and conditional on completion lab \(i\)'s contest share is

\[
\sigma_i=\frac{x_i}{X}.
\]

Lab \(i\)'s payoff is

\[
U_i
=
\Lambda(X)\{\sigma_iL-(1-\sigma_i)D\}
-x_iR(X).
\]

Rewrite the payoff as

\[
U_i
=
\Lambda(X)\{\sigma_i(L+D)-D\}
-x_iR(X).
\]

At a symmetric profile \(x_i=x_j=x\), \(X=2x\), \(\sigma_i=1/2\), and

\[
\frac{\partial\sigma_i}{\partial x_i}
=
\frac{x_j}{(x_i+x_j)^2}
=\frac{1}{4x}
=\frac{1}{2X}.
\]

The first-order condition is therefore

\[
\frac12\Lambda'(X)(L-D)
+\frac{\Lambda(X)}{2X}(L+D)
=
R(X)+\frac{X}{2}R'(X).
\]

Substituting temporary lead values gives

\[
\frac{S(q,\Delta)}{r+\mu}
\left[
\frac{\pi-\beta}{2}\Lambda'(X)
+\frac{\pi+\beta}{2X}\Lambda(X)
\right]
=
R(X)+\frac{X}{2}R'(X).
\]

Thus the task and scaling primitives enter through \(S(q,\Delta)\), locally \(eq'(C)\varepsilon B(q)\).

## 8. Joint-Profit Benchmark

The two labs' total payoff from completing the step is \(L-D\), because one lab's productive lead value is offset by the other lab's defensive loss. A joint-profit planner solves

\[
\max_X\ \Lambda(X)(L-D)-XR(X).
\]

The interior first-order condition is

\[
\Lambda'(X^J)(L-D)=R(X^J)+X^JR'(X^J).
\]

Evaluate the private marginal payoff at \(X^J\):

\[
M^P(X^J)
=
\frac12\Lambda'(X^J)(L-D)
+\frac{\Lambda(X^J)}{2X^J}(L+D)
-R(X^J)-\frac{X^J}{2}R'(X^J).
\]

Using the joint condition,

\[
M^P(X^J)
=
\frac{\Lambda(X^J)}{2X^J}(L+D)-\frac12R(X^J).
\]

Hence decentralized symmetric effort is locally above the joint-profit benchmark iff

\[
\frac{\Lambda(X^J)}{X^J}(L+D)>R(X^J).
\]

With temporary lead values, this condition becomes

\[
\frac{\Lambda(X^J)}{X^J}
\frac{\pi+\beta}{r+\mu}S(q,\Delta)
>
R(X^J).
\]

## 9. Social Benchmark

A social planner uses total social step value \(S^W(q,\Delta)\), not only private appropriable value. If \(\Psi(X)\) is an external cost of aggregate frontier compute, the social problem is

\[
\max_X\ \Lambda(X)S^W(q,\Delta)-XR(X)-\Psi(X).
\]

The interior condition is

\[
\Lambda'(X^S)S^W(q,\Delta)
=
R(X^S)+X^SR'(X^S)+\Psi'(X^S).
\]

Therefore racing can be socially excessive or socially insufficient. Defensive displacement and unpriced compute externalities push toward excessive racing. Consumer surplus, spillovers, and low appropriability push toward insufficient racing.

## Result

The revised paper's main mathematical claims reduce to:

- the shifted-link boundary sufficient statistic;
- bounded-menu saturation and moving-frontier nonsaturation;
- bounded scaling-law derivatives and local capability steps;
- exponential temporary lead values;
- the symmetric contest first-order condition;
- the joint-profit over-racing condition;
- the social planner wedge.
