| name | ueai-model-explain |
| description | Explain econ models/tools — GTAP, GEMPACK, regression (Stata/R), DID, IO — at undergrad level. Names actual command syntax, file paths, error messages. Triggers at stage 02 or /ueai-stage 02. |
Model & tools (stage 02)
Tools you may explain
| Tool | Typical artefact | Where errors live |
|---|
GEMPACK (tablo.exe, gemsim.exe, runGTAP.exe) | .tab (model), .cmf (command), .sl4 (solution), .har (header array) | .log and console |
| GTAP database 11 | base data .har, parameters .prm | runGTAP window |
| Stata | .do, .dta, .smcl log | _rc return code |
| R / RStudio | .R, .Rmd, .RData | console traceback |
| Python (pandas, statsmodels, linearmodels) | .py, .ipynb | traceback |
LaTeX (TeX Live, tabular, booktabs, estout) | .tex → .pdf | .log |
| Excel + Power Query | .xlsx | (light) |
What you produce
A filled 02_model/model_notes.md with:
- 工具与版本 — name and version (e.g.
GEMPACK 12.0, Stata 18 SE).
- 输入文件 — list every input artefact with relative path inside the project.
- 核心命令 — exact command lines or .do/.R snippets the student will run.
- 预期输出 — what files appear, what columns/coefficients to expect.
- 常见报错 — at least 3 likely errors with diagnosis.
- 模型假设 — for econometric models, the identifying assumption stated in plain Chinese.
Concrete patterns
GTAP shock setup (most common stage-02 case)
! tariff-shock.cmf — increase US tariff on imports of HS chapter 85 from China by 25 pp
File (new) tariffshock.sl4 ;
File (new) tariffshock.har ;
File rwsbase.har ;
File rwspara.har ;
Verbal Description = "US 25pp tariff on imports of electronics from China, 2017 base" ;
Auxiliary files = tariffshock ;
Method = Gragg ;
Steps = 3 6 9 ;
subintervals = 3 ;
automatic accuracy = yes ;
Shock tms("Electronics", "China", "USA") = 25 ;
Common errors:
*** Could not open file XXX.har → check cd was set to the model folder.*** Model is not square → forgot to close a Variable or Equation block in the .tab.*** Newton convergence failed → reduce shock size or increase subintervals.
Stata regression (DID)
* did-tariff.do
use evidence/data/firm_panel.dta, clear
xtset firm_id year
gen post = year >= 2018
gen treat = exposed_to_301 == 1
reghdfe lnvalue treat##post, absorb(firm_id year) cluster(firm_id)
esttab using 03_results/tab1_did.tex, replace booktabs se star(* 0.10 ** 0.05 *** 0.01)
IO / completion coefficient calc
Use Leontief inverse $(I-A)^{-1}$. In Stata: mata: L = luinv(I-A). In Python:
import numpy as np
L = np.linalg.inv(np.eye(n) - A)
Output template
# 模型与工具
项目题目：{{TOPIC}}
对应课程：{{COURSE}}
研究问题：{{QUESTION}}
## 本阶段任务
记录工具命令、模型设定、报错处理和输出解释。
## AI辅助记录
- 使用时间：...
- 使用工具：...
- 使用提示词：prompts/model-gtap-gempack.md（或 model-regression.md）
### 工具与版本
- GEMPACK 12.0 / GTAP database 11
- TeX Live 2023, latexmk
### 输入文件
- 02_model/tariff-shock.cmf
- 02_model/runGTAP.bat
- evidence/data/comtrade_ch_us_2018-2024.csv
### 核心命令
```cmf
! tariff-shock.cmf
File (new) tariffshock.sl4 ;
...
Shock tms("Electronics", "China", "USA") = 25 ;
预期输出
tariffshock.sl4 — solutiontariffshock.har — updated headers; relevant headers: qgdp, qxw, EV- 关注 China 的 EV、qgdp、qxw（出口数量），按部门看 Electronics、Steel
常见报错
Could not open file rwsbase.har → 检查工作目录；cd D:\GTAP\base 后再运行。Newton convergence failed → Steps = 3 6 9 12 增加细分步数。- ...
模型假设
- 完全竞争 + Armington 弹性
- 全局 Walras 平衡
- 关税收入回到代表性家庭
人工核验与修改
- 数据来源或课程材料核验：
- 教师要求对照：
- 人工修改说明：
本阶段产出
- 提交文件：02_model/model_notes.md
- 运行截图/日志位置：evidence/model/
## What you DO NOT do
- Do not invent coefficients or numbers — those come from stage 03 after the model actually runs.
- Do not write a multi-equation derivation unless explicitly asked.
- If the student lacks GEMPACK access, suggest the GTAP-in-Excel or a partial-equilibrium fallback (SMART, WITS).
