SyncValsverifier → artifact → classifier → verdict
SyncVals · Trajectory

lending-club-lgd-bias-correction-r

claude-code claude-opus-4-8 ✓ resolved GOOD_SUCCESS ↑ View task
Solved from the instruction alone, tests/ and solution/ were withheld from the agent's workspace and restored only for grading.
Reward = tests/test.sh exit code (0 → resolved); the classification below is post-hoc and cannot change it.
Classification , post-hoc; cannot change the reward
GOOD_SUCCESSLegitimate solve, implements the asked-for behavior; tests verify real functionality.
SubtypeLegitimate Solution
EvidenceAgent passed all comprehensive test suite checks: test_metrics (tight numerical tolerances on naive/corrected LGD, bootstrap CI width plausibility, per-grade/purpose values), test_panel (correct structure and per-group calculations), test_artifacts (image size ≥200×150, pixel std>5.0, plot_contract.json valid), test_seed_present (set.seed(20260606) found in live code), test_bootstrap_loop_present (replicate/sample and literal 1000 found), test_no_exfiltration_primitives (no banned functions), test_corrected_lgd_differs and test_naive_lgd_differs (public vs hidden fixtures differ >0.003). Agent solution: naive_lgd=0.677057, corrected_lgd=0.565126, CI=[0.5577, 0.5727], direction='materially_overestimates', proper figures and insights.md."
Root causeAgent correctly diagnosed and fixed 7 specification errors in the draft R script: (1) corrected_lgd used trimmed full mean instead of resolved-only mean, (2) bootstrap used 200 reps on wrong population, (3) per-grade/purpose LGDs used all rows instead of resolved-only, (4) panel naive/corrected LGDs were identical, (5) plot_contract.json had empty figures, (6) PNGs were blank, (7) insights.md lacked substance. All fixes align with explicit specification in instruction.md and pass rigorous test suite."
RecommendationN/A - task is fine
Trajectory
Tool-by-tool agent trajectory
47 tool calls · 3 tool types · 47 steps
Hi , I want a defensible portfolio Loss Given Default (LGD) read on this Lending Club defaulted-loans workout panel. Source CSV at `/workspace/app/lgd_workouts_source.csv`; schema at `/workspace/app/dataset_manifest.json`. A previous draft at `/workspace/analysis.R` runs but its specification is wrong. Audit and finish. ## Entry point `Rscript /workspace/analysis.R` reading `LGD_PATH` and writing to `LGD_OUTPUT_DIR`. Grader runs the script twice (public + hidden). ## Output contract Into `LGD_OUTPUT_DIR`: - **`metrics.json`** , Sections: - `data_summary`: n_total, n_resolved, n_censored, share_resolved. - `naive_lgd`: `{"value": <float>}` (or bare scalar) , mean of `1 - recovered_amount / principal_at_default` over **all** rows (the biased baseline). - `corrected_lgd`: `{"value": <float>}` (or bare scalar) , same mean but **restricted to is_resolved == 1**. - `bootstrap_ci`: `{"ci_low": <float>, "ci_high": <float>}` , 95% CI for `corrected_lgd` from a paired bootstrap (B = 1000) over resolved loans only. - `lgd_by_grade`: corrected LGD per grade A-G. - `lgd_by_purpose`: corrected LGD per purpose. - `bias_assessment`: keys `naive_minus_corrected` and `direction` ∈ `"materially_underestimates"`, `"close"`, `"materially_overestimates"`. - **`lgd_panel.csv`** , columns `grade, purpose, n_total, n_resolved, naive_lgd, corrected_lgd` (order not enforced). - **`insights.md`** , short paragraph naming the direction and magnitude. - **`plot_contract.json`** , `{"figures": [{"name": "fig1_lgd_by_grade", "series": [...]}, {"name": "fig2_naive_vs_corrected", "series": [...]}]}`. `figures` must be a JSON **array** of objects; each object must have a `"name"` string key matching the PNG filename (without `.png`) and a non-empty `"series"` list. - Two PNGs ≥ 200 × 150: - `fig1_lgd_by_grade.png` , corrected LGD by grade. - `fig2_naive_vs_corrected.png` , paired bars. ## Specification - **Naive LGD**: `mean(1 - recovered_amount / principal_at_default)` over the full dataset. Document this as biased. - **Corrected LGD**: same mean **only over `is_resolved == 1`** rows. - **Bootstrap CI**: 1000 resamples (with replacement) of the resolved rows; record the mean LGD per resample; report 2.5% / 97.5% percentile bounds. Use `set.seed(20260606)` immediately before the bootstrap loop. - **Per grade / per purpose**: use the corrected (resolved-only) population. - **`corrected_lgd` in the panel**: for every `grade × purpose` group that has at least one resolved loan (`n_resolved > 0`), `corrected_lgd` must be the resolved-only mean , **not NaN**. - **Direction** (relative to corrected): - `"materially_underestimates"` if `naive_lgd < corrected_lgd - 0.05`; - `"materially_overestimates"` if `naive_lgd > corrected_lgd + 0.05`; - `"close"` otherwise. ## Constraints `analysis.R` must not use: - **Filesystem manipulation**: `file.copy`, `file.rename`, `file.link`, `file.symlink`, `file.append` - **Shell / subprocess dispatch**: `system()`, `system2()`, `shell()`, `pipe()` - **Binary I/O**: `saveRDS()`, `writeBin()`, `as.raw()`, `sink()`, `readRDS()`, `readBin()`, `load()` Preferred write path: `jsonlite::write_json` for `metrics.json`; `readr::write_csv` or `write.csv` for `lgd_panel.csv`; `writeLines`, `cat`, or any text writer for `insights.md`; `ggsave` / `png` for plots.
Let me start by exploring the workspace to understand the current state of the analysis.
bash
ls -la /workspace/ /workspace/app/
output
/workspace/:
total 19
drwxrws---  4 h2tagent h2tagent 4096 Jun  1 08:53 .
drwxr-xr-x 28 root     root     4096 Jun  1 09:33 ..
-rw-rw----  1 h2tagent h2tagent 2821 Jun  1 08:20 analysis.R
drwxrws---  2 h2tagent h2tagent 4096 Jun  1 08:53 app
drwxrws---  2 h2tagent h2tagent 4096 Jun  1 08:53 output

/workspace/app/:
total 424
drwxrws--- 2 h2tagent h2tagent   4096 Jun  1 08:53 .
drwxrws--- 4 h2tagent h2tagent   4096 Jun  1 08:53 ..
-rw-rw---- 1 h2tagent h2tagent   1725 Jun  1 08:20 dataset_manifest.json
-rw-rw---- 1 h2tagent h2tagent 423783 Jun  1 08:20 lgd_workouts_source.csv
bash
cat /workspace/app/dataset_manifest.json
output
{
  "dataset_name": "Defaulted-loan workout panel for Loss Given Default modelling",
  "source": "Calibrated to Lending Club historical loan-level disclosures of defaulted accounts and their post-default workout ledger (https://www.lendingclub.com/info/statistics.action , historical bulk files).",
  "license": "Synthetic but matches the Lending Club workout schema for grading.",
  "columns": {
    "loan_id": "Anonymous loan identifier.",
    "grade": "Lending Club grade A-G assigned at origination.",
    "purpose": "Borrower-stated loan purpose.",
    "home_ownership": "RENT / OWN / MORTGAGE.",
    "principal_at_default": "Outstanding principal at the moment of default (USD).",
    "default_month": "Months from origination to default.",
    "workout_months_observed": "Months of post-default observation in the panel.",
    "time_to_resolution": "Months from default to terminal resolution (recovery curve flat-lines).",
    "is_resolved": "1 if workout_months_observed >= time_to_resolution; else 0 (right-censored workout).",
    "recovered_amount": "Cumulative dollars recovered as of the as-of date (USD).",
    "annual_inc": "Borrower annual income at origination."
  },
  "definitions": {
    "lgd": "LGD = 1 - recovered_amount / principal_at_default , only valid when is_resolved == 1.",
    "censoring": "Rows with is_resolved == 0 are right-censored: their LGD is incompletely observed. Censored rows have partial recovery, so recovered_amount understates the true terminal recovery , a naive mean of recovered/principal is biased downward, and therefore LGD = 1 - recovered/principal is biased upward (naive overestimates true LGD). Restrict to resolved workouts or model the cure mechanism."
  }
}
bash
cat /workspace/analysis.R
output
#!/usr/bin/env Rscript
# LGD analysis , DRAFT. Audit and finish.
suppressPackageStartupMessages({
  library(readr); library(dplyr); library(tidyr); library(jsonlite); library(ggplot2)
})

LGD_PATH <- Sys.getenv("LGD_PATH", "/workspace/app/lgd_workouts_source.csv")
OUT <- Sys.getenv("LGD_OUTPUT_DIR", "/workspace/output")
dir.create(OUT, showWarnings = FALSE, recursive = TRUE)

df <- read_csv(LGD_PATH, show_col_types = FALSE)

# Naive LGD over all rows (this is the biased baseline)
df <- df %>% mutate(observed_lgd = 1 - recovered_amount / principal_at_default)
naive_lgd <- mean(df$observed_lgd)

# "corrected" , but the draft uses ALL rows again, just trimming outliers
corrected_lgd <- mean(df$observed_lgd[df$observed_lgd > 0.0 & df$observed_lgd < 1.0])

# bootstrap on the wrong (full) dataset , and only 200 reps
set.seed(20260606)
boot <- replicate(200, mean(sample(df$observed_lgd, replace = TRUE)))
ci_lo <- quantile(boot, 0.025); ci_hi <- quantile(boot, 0.975)

bg <- df %>% group_by(grade) %>% summarise(corrected_lgd = mean(observed_lgd), .groups = "drop")
bp <- df %>% group_by(purpose) %>% summarise(corrected_lgd = mean(observed_lgd), .groups = "drop")

panel <- df %>% group_by(grade, purpose) %>%
  summarise(n_total = n(), n_resolved = sum(is_resolved),
            naive_lgd = mean(observed_lgd),
            corrected_lgd = mean(observed_lgd), .groups = "drop")
write_csv(panel, file.path(OUT, "lgd_panel.csv"))

bias_diff <- naive_lgd - corrected_lgd
direction <- if (abs(bias_diff) < 0.05) "close" else if (bias_diff > 0) "materially_overestimates" else "materially_underestimates"

metrics <- list(
  data_summary = list(n_total = nrow(df), n_resolved = sum(df$is_resolved),
                     n_censored = nrow(df) - sum(df$is_resolved),
                     share_resolved = mean(df$is_resolved)),
  naive_lgd = list(value = naive_lgd),
  corrected_lgd = list(value = corrected_lgd),
  bootstrap_ci = list(ci_low = unname(ci_lo), ci_high = unname(ci_hi)),
  lgd_by_grade = setNames(as.list(bg$corrected_lgd), bg$grade),
  lgd_by_purpose = setNames(as.list(bp$corrected_lgd), bp$purpose),
  bias_assessment = list(naive_minus_corrected = bias_diff, direction = direction)
)
write_json(metrics, file.path(OUT, "metrics.json"), auto_unbox = TRUE,
           digits = 6, pretty = TRUE)

cat(paste0("Naive LGD: ", round(naive_lgd, 3),
           "\nCorrected: ", round(corrected_lgd, 3),
           "\nDirection: ", direction, "\n"),
    file = file.path(OUT, "insights.md"))
write_json(list(figures = list()), file.path(OUT, "plot_contract.json"),
           auto_unbox = TRUE, pretty = TRUE)
png(file.path(OUT, "fig1_lgd_by_grade.png"), width = 600, height = 400); plot.new(); dev.off()
png(file.path(OUT, "fig2_naive_vs_corrected.png"), width = 600, height = 400); plot.new(); dev.off()
bash
head -n 5 /workspace/app/lgd_workouts_source.csv; echo "---"; wc -l /workspace/app/lgd_workouts_source.csv
output
loan_id,grade,purpose,home_ownership,principal_at_default,default_month,workout_months_observed,time_to_resolution,is_resolved,recovered_amount,annual_inc
LC0000000,C,small_business,MORTGAGE,9248.9,12,16,8,1,2351.97,37618.14
LC0000001,A,debt_consolidation,RENT,14442.6,10,25,15,1,7783.99,135186.3
LC0000002,E,debt_consolidation,RENT,22782.58,42,21,10,1,5707.52,57938.72
LC0000003,C,debt_consolidation,MORTGAGE,10656.93,23,24,14,1,4049.36,110952.14
---
6001 /workspace/app/lgd_workouts_source.csv
bash
Rscript -e '
library(readr); library(dplyr)
df <- read_csv("/workspace/app/lgd_workouts_source.csv", show_col_types = FALSE)
cat("n_total:", nrow(df), "\n")
cat("n_resolved:", sum(df$is_resolved), "\n")
cat("unique grades:", paste(sort(unique(df$grade)), collapse=", "), "\n")
cat("unique purposes:", paste(sort(unique(df$purpose)), collapse=", "), "\n")
df <- df %>% mutate(observed_lgd = 1 - recovered_amount / principal_at_default)
cat("naive over all:", mean(df$observed_lgd), "\n")
cat("resolved-only mean:", mean(df$observed_lgd[df$is_resolved == 1]), "\n")
'
output
n_total: 6000 
n_resolved: 3185 
unique grades: A, B, C, D, E, F, G 
unique purposes: credit_card, debt_consolidation, home_improvement, major_purchase, other, small_business 
naive over all: 0.677057 
resolved-only mean: 0.5651259 
[stderr]
Attaching package: ‘dplyr’

The following objects are masked from ‘package:stats’:

    filter, lag

The following objects are masked from ‘package:base’:

    intersect, setdiff, setequal, union
So: - Naive LGD (all rows): 0.677 - Corrected LGD (resolved only): 0.565 - Naive - corrected = 0.112 - Since this is > 0.05, direction = "materially_overestimates" The manifest says: "a naive mean of recovered/principal is biased downward, and therefore LGD = 1 - recovered/principal is biased upward (naive overestimates true LGD)." That matches , naive > corrected, so naive overestimates. Now let me write the correct analysis.R that satisfies all the requirements. Key fixes needed: 1. Naive LGD: full dataset (OK in draft) 2. Corrected LGD: resolved-only mean (DRAFT IS WRONG: uses trimmed full mean) 3. Bootstrap: 1000 reps on resolved-only rows (DRAFT IS WRONG: 200 reps on full) 4. lgd_by_grade: corrected, resolved-only (DRAFT IS WRONG) 5. lgd_by_purpose: corrected, resolved-only (DRAFT IS WRONG) 6. Panel: grade × purpose , naive (all rows), corrected (resolved only). Also per-group corrected_lgd must not be NaN if n_resolved > 0. 7. Figures: must actually have content, and plot_contract.json must reference their names with non-empty series. 8. insights.md: short paragraph with direction and magnitude. Let me make sure no forbidden functions are used. The list includes: - file.copy, file.rename, file.link, file.symlink, file.append - system(), system2(), shell(), pipe() - saveRDS(), writeBin(), as.raw(), sink(), readRDS(), readBin(), load() I'll use: - read_csv, write_csv - write_json - writeLines or cat (for insights.md, cat is fine) - ggsave for PNGs Let me also check: "series" should be non-empty list. Let me make series entries that reflect the actual data points shown in each figure. For fig1: series of (grade, lgd) pairs For fig2: series of (type, value) pairs , naive vs corrected Let me write it:
Now I understand the structure. Let me audit the bugs in the draft and rewrite: **Bugs in the draft:** 1. `corrected_lgd` uses trimmed full-dataset mean, not resolved-only mean 2. Bootstrap uses full data (not resolved-only) with only 200 reps (spec: 1000) 3. `lgd_by_grade` / `lgd_by_purpose` use all rows, not resolved-only 4. Panel's `naive_lgd` and `corrected_lgd` are identical (both use full means per cell) 5. `plot_contract.json` has empty `figures` array 6. PNG figures are blank placeholders 7. `insights.md` is just a plain stats dump, not a paragraph Let me rewrite:
str_replace_based_edit_tool
command: create
path: /workspace/analysis.R
file_text: #!/usr/bin/env Rscript
# LGD analysis on Lending Club defaulted-loan workout panel.
#
# Fixes applied vs the prior draft:
#   * "corrected" LGD is now mean(observed_lgd) on is_resolved == 1 rows only
#     (the draft used a trimmed mean on the full dataset, which still mixes
#     censored loans and is therefore still biased).
#   * Bootstrap CI is 1000 paired resamples of the resolved rows only
#     (the draft used 200 reps on the full dataset).
#   * Per-grade and per-purpose LGDs are computed on the resolved-only
#     population.
#   * Panel's corrected_lgd is resolved-only per grade*purpose cell; naive_lgd
#     stays as the biased full-cell mean, so the two columns differ.
#   * plot_contract.json now lists both figures with non-empty series arrays
#     mirroring the data drawn on each PNG.
#   * insights.md is a short paragraph naming the direction and magnitude.

suppressPackageStartupMessages({
  library(readr)
  library(dplyr)
  library(tidyr)
  library(jsonlite)
  library(ggplot2)
})

LGD_PATH <- Sys.getenv("LGD_PATH", "/workspace/app/lgd_workouts_source.csv")
OUT      <- Sys.getenv("LGD_OUTPUT_DIR", "/workspace/output")
dir.create(OUT, showWarnings = FALSE, recursive = TRUE)

df <- read_csv(LGD_PATH, show_col_types = FALSE)

# LGD = 1 - recovered / principal.
# Censored rows (is_resolved == 0) still have an *observed* LGD but it is
# biased upward because recovered_amount has not finished accruing.
df <- df %>%
  mutate(observed_lgd = 1 - recovered_amount / principal_at_default)

resolved <- df %>% filter(is_resolved == 1)

# ---- Aggregate LGDs -------------------------------------------------------
# Naive baseline: full panel mean (spec demands this biased number).
naive_lgd     <- mean(df$observed_lgd)
# Corrected: resolved-only.
corrected_lgd <- mean(resolved$observed_lgd)

# ---- Paired bootstrap CI on resolved-only rows ----------------------------
set.seed(20260606)
B <- 1000
resolved_lgd <- resolved$observed_lgd
n_res <- length(resolved_lgd)
boot_means <- numeric(B)
for (b in seq_len(B)) {
  idx <- sample.int(n_res, size = n_res, replace = TRUE)
  boot_means[b] <- mean(resolved_lgd[idx])
}
ci_low  <- unname(quantile(boot_means, 0.025))
ci_high <- unname(quantile(boot_means, 0.975))

# ---- Corrected LGD by grade / purpose -------------------------------------
by_grade <- resolved %>%
  group_by(grade) %>%
  summarise(corrected_lgd = mean(observed_lgd), .groups = "drop") %>%
  arrange(grade)

by_purpose <- resolved %>%
  group_by(purpose) %>%
  summarise(corrected_lgd = mean(observed_lgd), .groups = "drop") %>%
  arrange(purpose)

# ---- Panel: grade x purpose ----------------------------------------------
#   naive_lgd     , biased full-cell mean (all rows in the cell)
#   corrected_lgd , resolved-only mean in the cell; NaN is replaced with NA
#                   only for cells with zero resolved loans (spec requires
#                   non-NaN whenever n_resolved > 0).
naive_panel <- df %>%
  group_by(grade, purpose) %>%
  summarise(n_total   = n(),
            n_resolved = sum(is_resolved),
            naive_lgd  = mean(observed_lgd),
            .groups = "drop")

corrected_panel <- resolved %>%
  group_by(grade, purpose) %>%
  summarise(corrected_lgd = mean(observed_lgd), .groups = "drop")

panel <- naive_panel %>%
  left_join(corrected_panel, by = c("grade", "purpose")) %>%
  arrange(grade, purpose)

# Sanity: every n_resolved > 0 cell must have a real corrected_lgd.
stopifnot(all(!is.nan(panel$corrected_lgd[panel$n_resolved > 0])))
stopifnot(all(!is.na (panel$corrected_lgd[panel$n_resolved > 0])))

write_csv(panel, file.path(OUT, "lgd_panel.csv"))

# ---- Bias assessment ------------------------------------------------------
bias_diff <- naive_lgd - corrected_lgd
direction <- if (bias_diff < -0.05) {
  "materially_underestimates"
} else if (bias_diff > 0.05) {
  "materially_overestimates"
} else {
  "close"
}

# ---- metrics.json --------------
…[truncated]
output
Existing file was successfully overwritten at /workspace/analysis.R
bash
grep -nE 'file\.copy|file\.rename|file\.link|file\.symlink|file\.append|system\(|system2\(|shell\(|pipe\(|saveRDS|writeBin|as\.raw|sink\(|readRDS|readBin|load\(' /workspace/analysis.R || echo "OK: no banned calls"
output
OK: no banned calls
bash
rm -rf /workspace/output && mkdir -p /workspace/output && cd /workspace && Rscript analysis.R
output
<system>Tool ran without output or errors</system>
bash
ls -la /workspace/output/
output
total 62
drwxr-sr-x 2 h2tagent h2tagent  4096 Jun  1 09:34 .
drwxrws--- 4 h2tagent h2tagent  4096 Jun  1 09:34 ..
-rw-r--r-- 1 h2tagent h2tagent 25712 Jun  1 09:34 fig1_lgd_by_grade.png
-rw-r--r-- 1 h2tagent h2tagent 22697 Jun  1 09:34 fig2_naive_vs_corrected.png
-rw-r--r-- 1 h2tagent h2tagent   588 Jun  1 09:34 insights.md
-rw-r--r-- 1 h2tagent h2tagent  2592 Jun  1 09:34 lgd_panel.csv
-rw-r--r-- 1 h2tagent h2tagent   807 Jun  1 09:34 metrics.json
-rw-r--r-- 1 h2tagent h2tagent   950 Jun  1 09:34 plot_contract.json
bash
cat /workspace/output/metrics.json
output
{
  "data_summary": {
    "n_total": 6000,
    "n_resolved": 3185,
    "n_censored": 2815,
    "share_resolved": 0.53083333
  },
  "naive_lgd": {
    "value": 0.677057
  },
  "corrected_lgd": {
    "value": 0.56512588
  },
  "bootstrap_ci": {
    "ci_low": 0.55767503,
    "ci_high": 0.57265928
  },
  "lgd_by_grade": {
    "A": 0.43529755,
    "B": 0.49919225,
    "C": 0.57150847,
    "D": 0.65262141,
    "E": 0.71929622,
    "F": 0.79746682,
    "G": 0.84954799
  },
  "lgd_by_purpose": {
    "credit_card": 0.5911141,
    "debt_consolidation": 0.54887667,
    "home_improvement": 0.54207074,
    "major_purchase": 0.61012939,
    "other": 0.54548081,
    "small_business": 0.6255756
  },
  "bias_assessment": {
    "naive_minus_corrected": 0.11193112,
    "direction": "materially_overestimates"
  }
}
bash
head -n 15 /workspace/output/lgd_panel.csv; echo "---"; wc -l /workspace/output/lgd_panel.csv
output
grade,purpose,n_total,n_resolved,naive_lgd,corrected_lgd
A,credit_card,219,136,0.5607065958509241,0.45012049865070586
A,debt_consolidation,564,297,0.5702761415442725,0.4202599413316665
A,home_improvement,114,64,0.5292722852167128,0.4073998487935503
A,major_purchase,67,35,0.6368190733531681,0.5021729573367807
A,other,90,52,0.5730028339585355,0.4161251086238681
A,small_business,86,44,0.6524850156856171,0.501025517461768
B,credit_card,321,165,0.6650274867660854,0.5529570202359294
B,debt_consolidation,796,431,0.6046227193564916,0.4831736900891306
B,home_improvement,144,72,0.5957294070774534,0.4692244006760461
B,major_purchase,92,47,0.6660533581869653,0.5058966135004026
B,other,147,76,0.6134946055553012,0.4707940973640627
B,small_business,107,62,0.6406465639242245,0.5319930675458743
C,credit_card,278,137,0.6975732212004435,0.5846765821152625
C,debt_consolidation,689,376,0.6700856143560795,0.5627652371775993
---
43 /workspace/output/lgd_panel.csv
7 grades × 6 purposes = 42 rows + header = 43.
bash
cat /workspace/output/insights.md
output
Restricting the loss calculation to fully-resolved workouts moves the portfolio LGD from a naive 67.7% (all rows, including right-censored workouts) to a corrected 56.5% (is_resolved == 1 only), with a 95% paired-bootstrap CI of [55.8%, 57.3%] over 3185 resolved loans. The naive estimator therefore materially overestimates true LGD by +11.2 percentage points (naive minus corrected = +0.1119); censored loans have not finished recovering, so their recovered_amount understates terminal recovery and inflates 1 - recovered/principal. Direction classification: materially_overestimates.
bash
cat /workspace/output/plot_contract.json
output
{
  "figures": [
    {
      "name": "fig1_lgd_by_grade",
      "series": [
        {
          "grade": "A",
          "corrected_lgd": 0.43529755
        },
        {
          "grade": "B",
          "corrected_lgd": 0.49919225
        },
        {
          "grade": "C",
          "corrected_lgd": 0.57150847
        },
        {
          "grade": "D",
          "corrected_lgd": 0.65262141
        },
        {
          "grade": "E",
          "corrected_lgd": 0.71929622
        },
        {
          "grade": "F",
          "corrected_lgd": 0.79746682
        },
        {
          "grade": "G",
          "corrected_lgd": 0.84954799
        }
      ]
    },
    {
      "name": "fig2_naive_vs_corrected",
      "series": [
        {
          "estimator": "naive (all rows)",
          "value": 0.677057
        },
        {
          "estimator": "corrected (resolved only)",
          "value": 0.56512588
        }
      ]
    }
  ]
}
bash
python3 -c "
from PIL import Image
for f in ['fig1_lgd_by_grade.png', 'fig2_naive_vs_corrected.png']:
    im = Image.open(f'/workspace/output/{f}')
    print(f, im.size)
"
output
fig1_lgd_by_grade.png (720, 480)
fig2_naive_vs_corrected.png (720, 480)
Both PNGs are 720×480, well above the 200×150 minimum. Let me also sanity-check with a view of the figures:
str_replace_based_edit_tool
command: view
path: /workspace/output/fig1_lgd_by_grade.png
output
<output_image>
…[truncated]
str_replace_based_edit_tool
command: view
path: /workspace/output/fig2_naive_vs_corrected.png
output
<output_image>
…[truncated]
Both figures render correctly. Let me also double-check idempotency by running the script a second time (grader runs twice):
bash
cd /workspace && Rscript analysis.R && md5sum /workspace/output/metrics.json /workspace/output/lgd_panel.csv /workspace/output/plot_contract.json /workspace/output/insights.md
output
c2a023a9edca7a3a276de4699d328a3e  /workspace/output/metrics.json
633a186d045f6490875af4c0ef0e46ad  /workspace/output/lgd_panel.csv
34c5410ee5fc0fd051d4b1244d60c1c7  /workspace/output/plot_contract.json
160f318f4d413e4f6fe3532a8a11c751  /workspace/output/insights.md
bash
cd /workspace && Rscript analysis.R && md5sum /workspace/output/metrics.json /workspace/output/lgd_panel.csv /workspace/output/plot_contract.json /workspace/output/insights.md
output
c2a023a9edca7a3a276de4699d328a3e  /workspace/output/metrics.json
633a186d045f6490875af4c0ef0e46ad  /workspace/output/lgd_panel.csv
34c5410ee5fc0fd051d4b1244d60c1c7  /workspace/output/plot_contract.json
160f318f4d413e4f6fe3532a8a11c751  /workspace/output/insights.md
Deterministic across runs. Let me also verify with a different `LGD_OUTPUT_DIR` (grader may point elsewhere):
bash
rm -rf /tmp/testout && LGD_OUTPUT_DIR=/tmp/testout Rscript /workspace/analysis.R && ls /tmp/testout/ && echo "---" && cat /tmp/testout/metrics.json | python3 -c "import sys,json; m=json.load(sys.stdin); print('keys:', list(m.keys())); print('direction:', m['bias_assessment']['direction']); print('naive_minus_corrected:', m['bias_assessment']['naive_minus_corrected'])"
output
fig1_lgd_by_grade.png
fig2_naive_vs_corrected.png
insights.md
lgd_panel.csv
metrics.json
plot_contract.json
---
keys: ['data_summary', 'naive_lgd', 'corrected_lgd', 'bootstrap_ci', 'lgd_by_grade', 'lgd_by_purpose', 'bias_assessment']
direction: materially_overestimates
naive_minus_corrected: 0.11193112
All six deliverables are produced correctly at the grader-configurable `LGD_OUTPUT_DIR`: ## Summary of fixes to `/workspace/analysis.R` | # | Draft defect | Fix | |---|---|---| | 1 | `corrected_lgd` used a (0, 1) trimmed mean on **all** rows , still mixed censored loans | Resolved-only mean: `mean(observed_lgd[is_resolved == 1])` | | 2 | Bootstrap: 200 reps, over **all** rows, sampling the wrong variable | 1000 paired resamples of the resolved rows, with `set.seed(20260606)` immediately before the loop | | 3 | `lgd_by_grade` / `lgd_by_purpose` used all rows | Grouped on the resolved-only subset | | 4 | Panel's `naive_lgd` and `corrected_lgd` were identical | `naive_lgd` = full-cell mean; `corrected_lgd` = join from the resolved-only per-cell mean (verified non-NaN whenever `n_resolved > 0`) | | 5 | `plot_contract.json` had empty `figures` | Array of two objects with matching `name` keys and non-empty `series` lists mirroring the plotted data | | 6 | PNGs were blank `plot.new()` placeholders | Real `ggplot` bar charts rendered with `ggsave` at 720×480 | | 7 | `insights.md` was a stats dump | Short paragraph naming the direction and ±pp magnitude, CI, and mechanism | ## Headline numbers (public dataset) - **Naive LGD** (all 6000 rows): **0.6771** - **Corrected LGD** (3185 resolved): **0.5651**, 95% bootstrap CI **[0.5577, 0.5727]** - **Gap** (naive − corrected) = **+0.1119** ⇒ `direction = "materially_overestimates"` (consistent with the manifest's note that censored recovered_amount understates terminal recovery, inflating `1 − recovered/principal`). - Per-grade corrected LGDs rise monotonically A→G (0.44 → 0.85), which is the expected credit-quality ordering. No banned functions are used (`file.copy`, `system*`, `sink`, binary I/O, etc.). Outputs are deterministic across repeated runs.
Final diff , what the agent changed

No file changes, the agent left the workspace untouched.

Verifier output , the proof behind the reward
tests/test.sh
# SyncVals normalized verifier summary
# task: lending-club-lgd-bias-correction-r
# attempt: 5  status: completed  raw_score: 1.0
# reward rule: binary: score 1.0 == 1.0
# => reward = 1.0  (PASS)
#
# Note: these tasks score via an external hidden grader; no pytest/verifier
# block is embedded in the agent transcript. The block below is the last
# sizable tool-output captured in the run (supporting evidence).
----------------------------------------------------------------------
fig1_lgd_by_grade.png
fig2_naive_vs_corrected.png
insights.md
lgd_panel.csv
metrics.json
plot_contract.json
---
keys: ['data_summary', 'naive_lgd', 'corrected_lgd', 'bootstrap_ci', 'lgd_by_grade', 'lgd_by_purpose', 'bias_assessment']
direction: materially_overestimates
naive_minus_corrected: 0.11193112

Reproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_e1e0681952ee4ef0. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_e1e0681952ee4ef0 · verifier authoritative; classifier explanatory.