Assumptions and verification
Claim revision: catalog:aecc819b77f109adebac5125e992a72f2fb29dbd102364c427171e979fa770b8
Standing assumptions: The article is a four-page empirical report of one field experiment (printed pp. 594-597 are PDF pp. 1-4; PDF p. 5 is a copyright notice). It states no theorem, proposition, lemma or proof and uses no potential-outcome notation; its only displayed formula is the regression model in Section III. The setting, as printed (read from the page images):
Population and design (Section II, p. 595, PDF p. 2): “We contacted by email all 189 UN Permanent Missions from member states that had current diplomatic relations with the United States at the time of the intervention.” and “Of the 189 missions contacted, 94 were randomly assigned the peer treatment and 95 the world affairs treatment.” The paper says nothing more about the assignment mechanism; the validators read it as complete randomization of a fixed number of missions (94 of 189) to the peer treatment.
Outcomes (Section II, p. 595, PDF p. 2): “Analysis was conducted with treatment assignment blinded. Our outcome of interest is response to emails. We code separately ‘interest response’ for emails that had some indication of interest, and ‘any response’, for any type of reply to the email, including interest responses, notification of a change in the Permanent Representative and declination to participate. Table 1 shows number and percentage of responses by treatment group.”
Table 1 (p. 595, PDF p. 2), “Response by treatment.”: Peers: Countries 94; Any response, Count 10, Per cent 10.64; Interest response, Count 10, Per cent 10.64. World affairs: Countries 95; Any response, Count 10, Per cent 10.53; Interest response, Count 7, Per cent 7.37. Note: “‘Per cent’ columns represent count as a percentage of countries assigned to respective treatment group. ‘Interest’ responses are a subset of ‘any’ responses.”
Covariates (Section II, Country data, p. 595, PDF p. 2): “We follow Fisman and Miguel (2007) in selection of control variables, and use the replication files for their article as a source for data on these variables (Fisman and Miguel 2015). As expected given randomization, we find no statistically or substantively significant differences in covariate balance between the two groups. For missing covariate entries, we follow Lin, Green, and Coppock (2015) and use mean imputation.”
Estimation (Section III; the display is at the foot of p. 595, PDF p. 2, and the sentence continues at the top of the left column of p. 596, PDF p. 3, below Table 2), as printed: “We conduct an ordinary least squares (OLS) regression of the outcomes on an indicator for assignment to peer treatment. The model we estimate is $$Y = \beta_0 + \beta_1 Peers + \boldsymbol{X}\gamma + \epsilon$$ where $\beta_1$ represents the peer assignment indicator, $\boldsymbol{X}$ represents the vector of covariates, including country-level covariates and indicators for region and $\varepsilon$ is a disturbance with $E[\varepsilon|Peers, \boldsymbol{X}] = 0$. Note that, when covariates are not included, this estimator of $\beta_1$ reduces to the well-known difference-in-means.” The display prints the disturbance as $\epsilon$ and the sentence below it prints $\varepsilon$; they are the same object. The clause “where $\beta_1$ represents the peer assignment indicator” is the misprint of finding P036-E001 (see P036-T1). Next paragraph (p. 596): “We first report estimates without covariate adjustment (the difference-in-means), followed by specifications controlling for country-level covariates and indicators for region. Summary results for OLS regressions are presented in Table 2.”
Table 2 (p. 596, PDF p. 3), “Ordinary least squares regressions: any response.”: columns (1), (2), (3) under “Any response” and (4), (5), (6) under “Interest response”. Treatment effect: 0.001, $-0.010$, $-0.001$, 0.033, 0.023, 0.033, with (0.045), (0.045), (0.046), (0.042), (0.042), (0.043) in parentheses below. Control mean: 0.105, 0.111, 0.106, 0.074, 0.078, 0.074, with (0.032), (0.033), (0.033), (0.027), (0.028), (0.028) below. Country characteristics: No, Yes, Yes, No, Yes, Yes. Region indicators: No, No, Yes, No, No, Yes. Note: “‘Any response’ indicator is the dependent variable for specifications 1, 2 and 3. ‘Interest response’ indicator is the dependent variable for specifications 4, 5 and 6. Heteroscedasticity-consistent SEs are reported in parentheses, using MacKinnon and White (1985) HC2 estimators; these estimators are generally conservative under a randomization model (Samii and Aronow 2012). ‘Country characteristics’ indicates inclusion of country-level covariates in the specification. Covariates are number of diplomats in the UN mission, corruption index, log per capita income, average government wage divided by per capita income, log weighted distance between country and US populations, log total trade with the USA and dummies for whether the country received US economic aid and US military aid. ‘Region indicators’ are dummy variables for the region in which the country is located: Africa, Asia, Europe, South America or the Middle East; North America is the excluded region.”
Scope of the targets. None of the headline claims P036-H1 to P036-H6 is a mathematical statement: H1 to H4 are empirical estimates and statements about their statistical significance, H5 describes the population contacted, and H6 is an interpretive remark; so there is no headline target. The four confirmed errors are all rated Minor, so there is no result_touched_by_finding target, and no validator gave a counterexample to a printed statement, so there is no counterexample target. Two confirmed errors have a correction that changes a mathematical statement and each gets a corrected-statement target: P036-E001 (the coefficient $\beta_1$ named as the assignment indicator in the sentence that defines the terms of the regression model) and P036-N003 (the conservativeness of the HC2 standard errors, attributed for all six columns of Table 2 to a paper that proves it for the regression without covariates only). Not targets: P036-E002 (the title of Table 2 names one of its two outcomes) and P036-E003 (‘authors(s)’ and a citation year), whose corrections change no mathematical statement; P036-N005 (a clarity note); P036-N001, P036-N008 and P036-N009 (not confirmed; the exact countermodels in the P036-N001 artifact concern estimands that Sol found the paper does not claim); P036-N002, P036-N004, P036-N006 and P036-N007 (undetermined).
Effective claim (source TeX): [Printed; note to Table 2, third sentence; it applies to the standard errors in parentheses in all six columns, of which (2), (3), (5) and (6) include covariates] “Heteroscedasticity-consistent SEs are reported in parentheses, using MacKinnon and White (1985) HC2 estimators; these estimators are generally conservative under a randomization model (Samii and Aronow 2012).”
[Corrected; Sol's smallest_repair, verbatim] “Restrict the cited justification to unadjusted specifications: 'HC2 standard errors are reported; for specifications (1) and (4), the corresponding variance estimator is conservative in expectation under complete randomization (Samii and Aronow 2012).' An adjusted-regression justification would require a separate appropriate result and its conditions.”
[Mathematical content of the corrected sentence, with every hypothesis; from the validator's derivation.md, sections 1 and 2] Setting. $N$ units $i=1,\dots,N$ with fixed potential outcomes $Y_i(1),Y_i(0)\in\mathbb{R}$. Integers $n_1\ge 2$ and $n_0\ge 2$ with $n_1+n_0=N$. Complete randomization: the set of treated units is uniformly distributed over the $\binom{N}{n_1}$ subsets of $\{1,\dots,N\}$ of size $n_1$; $T_i\in\{0,1\}$ indicates that unit $i$ is treated, and the observed outcome is $Y_i=Y_i(T_i)$. Every expectation and variance below is over this assignment alone. Population quantities: $\mu_w=N^{-1}\sum_i Y_i(w)$ and $S_w^2=(N-1)^{-1}\sum_i (Y_i(w)-\mu_w)^2$ for $w\in\{0,1\}$; $\tau_i=Y_i(1)-Y_i(0)$, $\bar\tau=\mu_1-\mu_0$ and $S_\tau^2=(N-1)^{-1}\sum_i(\tau_i-\bar\tau)^2$. Sample quantities: $\bar Y_1=n_1^{-1}\sum_{i:T_i=1}Y_i$, $\bar Y_0=n_0^{-1}\sum_{i:T_i=0}Y_i$, $s_1^2=(n_1-1)^{-1}\sum_{i:T_i=1}(Y_i-\bar Y_1)^2$ and $s_0^2=(n_0-1)^{-1}\sum_{i:T_i=0}(Y_i-\bar Y_0)^2$. Regression without covariates (specifications (1) and (4)): ordinary least squares of $Y_i$ on $D_i=(1,T_i)'$, with $D'D=\sum_i D_iD_i'=\begin{pmatrix}N&n_1\\ n_1&n_1\end{pmatrix}$, coefficient vector $(\hat\alpha,\hat\tau)'=(D'D)^{-1}\sum_i D_iY_i$, residuals $e_i=Y_i-\hat\alpha-\hat\tau T_i$ and leverages $h_i=D_i'(D'D)^{-1}D_i$. The HC2 covariance matrix is $(D'D)^{-1}\big(\sum_i \tfrac{e_i^2}{1-h_i}D_iD_i'\big)(D'D)^{-1}$, and $\hat V_{HC2}$ denotes its diagonal entry for the coefficient on $T$. Claims. (a) For every assignment, $\hat\tau=\bar Y_1-\bar Y_0$ and $\hat\alpha=\bar Y_0$; $h_i=1/n_1$ if $T_i=1$ and $h_i=1/n_0$ if $T_i=0$. (b) For every assignment, $$\hat V_{HC2}=\sum_{i:T_i=1}\frac{e_i^2}{n_1^2(1-1/n_1)}+\sum_{i:T_i=0}\frac{e_i^2}{n_0^2(1-1/n_0)}=\frac{s_1^2}{n_1}+\frac{s_0^2}{n_0},$$ the Neyman variance estimator. (c) $E[\hat\tau]=\mu_1-\mu_0$ and $$\mathrm{Var}(\hat\tau)=\frac{S_1^2}{n_1}+\frac{S_0^2}{n_0}-\frac{S_\tau^2}{N}.$$ (d) $E[s_1^2]=S_1^2$ and $E[s_0^2]=S_0^2$, hence $$E[\hat V_{HC2}]-\mathrm{Var}(\hat\tau)=\frac{S_\tau^2}{N}\ \ge\ 0,$$ with equality if and only if $\tau_i$ is the same for every unit. This is the sense of ‘conservative in expectation’. (e) The paper's two instances ($N=189$, $n_1=94$, $n_0=95$; for a binary outcome with $k$ ones among $n$ observations the sample variance is $k(n-k)/[n(n-1)]$): specification (1), ‘any response’, counts $10$ and $10$: $\hat V_{HC2}=\tfrac{10\cdot 84}{94^2\cdot 93}+\tfrac{10\cdot 85}{95^2\cdot 94}=\tfrac{50039}{24720919}$, whose square root is $0.04499\ldots$ (printed $0.045$); specification (4), ‘interest response’, counts $10$ and $7$: $\hat V_{HC2}=\tfrac{10\cdot 84}{94^2\cdot 93}+\tfrac{7\cdot 88}{95^2\cdot 94}=\tfrac{1080506}{618022975}$, whose square root is $0.04181\ldots$ (printed $0.042$). Not asserted by the corrected sentence: that the realized $\hat V_{HC2}$ is at least $\mathrm{Var}(\hat\tau)$ for every assignment; that $E[\sqrt{\hat V_{HC2}}]\ge\sqrt{\mathrm{Var}(\hat\tau)}$; or any property of the standard errors of the specifications with covariates, (2), (3), (5) and (6).
: SAP.P036.T2Statement
Theorem: SAP.P036.T2
Statement hash: cca04d1c8e82cf6e7fdda6ba8e3544980ce53ae15683691c3d5fab16de77a4c1
Statement definition: SAP.P036.T2Statement
Certificate. 20261103T230539Z
Declaration review: faithful; 2026-11-04T12:52:04Z; binding v2
Evidence scope: Certification checks formal proof objects. Statement fidelity is a model judgment. Author review is separate.
Proof dependencies: Independently extracted
Manifest annotation reconciliation: Effective use follows the source-bound dependency observation; original annotations are retained in the crosswalk.
AronowAudit.P036.armMean_congr: observed used
AronowAudit.P036.armSS_formula: observed used
AronowAudit.P036.assignments_card: observed used
AronowAudit.P036.assignments_nonempty: observed used
AronowAudit.P036.designVariance_congr: observed used
AronowAudit.P036.designVariance_second_moment: observed used
AronowAudit.P036.designVariance_sub_const: observed used
AronowAudit.P036.design_complement: observed used
AronowAudit.P036.expected_peer_indicator: observed used
AronowAudit.P036.expected_peer_pair: observed used
AronowAudit.P036.expected_sample_mean: observed used
AronowAudit.P036.expected_sample_total: observed used
AronowAudit.P036.expected_sample_total_sq: observed used
AronowAudit.P036.expected_sample_variance: observed used
AronowAudit.P036.observed_arm_quantities: observed used
AronowAudit.P036.pair_inclusion_count: observed used
AronowAudit.P036.populationVariance_nonneg: observed used
AronowAudit.P036.populationVariance_zero_iff_constant: observed used
AronowAudit.P036.randomization_unbiased_effect: observed used
AronowAudit.P036.randomization_unbiased_variances: observed used
AronowAudit.P036.randomization_variance_identity: observed used
AronowAudit.P036.residual_by_arm: observed used
AronowAudit.P036.sampleVariance_congr: observed used
AronowAudit.P036.sample_total_variance: observed used
AronowAudit.P036.single_inclusion_count: observed used
AronowAudit.P036.sum_linear_combination_sq: observed used
AronowAudit.P036.sum_peers_mul: observed used
AronowAudit.P036.weighted_pair_sum: observed used
Source and evidence metadata · sap-2026-11-08-assured-release