| Investigation Title | SIC Title | SIC Code | LLM Reasoning |
|---|---|---|---|
| Crystalline Silicon Photovoltaic Cells | Nonclassifiable Establishments | 9999 | None of the listed industries correspond to photovoltaic cell manufacturing; thus the case is best classified as nonclassifiable. |
| Large Residential Washers | Bolts, Nuts, Screws, Rivets, and Washers | 3452 | The keyword "washers" matches the SIC 3452 industry for bolt, nut, screw, rivet, and washer manufacturing, and its NAICS counterpart 332722. |
| Leather Wearing Apparel | Leather Goods, NEC | 3199 | The title refers to apparel made of leather, aligning best with leather goods manufacturing (SIC 3199.0 / NAICS 316999.0). |
| Fish | Fish and Seafoods | 5146 | The title directly references fish, matching the Fish and Seafoods wholesale industry. |
| Fresh Cut Roses | Fresh Fruits and Vegetables | 5148 | Fresh cut roses are a type of fresh produce best matched with the Fresh Fruits and Vegetables Wholesalers industry. |
| Motor Vehicles and Chassis and Bodies Thereof | Truck and Bus Bodies | 3713 | The case title focuses on motor vehicles, chassis, and bodies, matching the Motor Vehicle Body Manufacturing industry. |
| Fishing Rods and Parts Thereof | Metal Shower Rods | 3432 | Fishing rods are a type of metal (or fabricated) rod product, best fitting the Metal Shower Rods manufacturing industry and its associated NAICS category of miscellaneous fabricated metal products. |
| Tubeless Tire Valves | Industrial Valves | 3491 | Tubeless tire valves are a type of industrial valve component, best fitting the Industrial Valve Manufacturing category. |
| Heavyweight Motorcycles | Motorcycles, Bicycles, and Parts | 3751 | Direct match to motorcycle manufacturing. |
| Stainless Steel and Alloy Tool Steel | Steel Foundries, NEC | 3325 | Stainless and alloy tool steels are typically produced in steel foundries, matching the SIC 3325 and NAICS 331513 categories. |
| Nonrubber Footwear | Footwear, Except Rubber, NEC | 3149 | Direct match to nonrubber footwear manufacturing. |
| Carbon and Certain Alloy Tool Steel Products | Steel Foundries, NEC | 3325 | The case involves manufacturing of specialized tool steel, which is typically produced in steel foundries, matching SIC 3325 and NAICS 331513. |
| Unwrought Copper | Primary Smelting and Refining of Copper | 3331 | Unwrought copper refers to the raw refined copper produced in primary smelting and refining operations. |
| Canned Tuna Fish | Canned and Cured Fish and Seafood | 2091 | Direct match to canned and cured fish and seafood industry. |
| Potassium Permanganate | Nonclassifiable Establishments | 9999 | Potassium Permanganate is a chemical product not covered by the listed manufacturing industries, so it falls under the Nonclassifiable/Unclassified category. |
| Nonrubber Footwear | Footwear, Except Rubber, NEC | 3149 | Directly matches the industry for footwear manufacturing excluding rubber products. |
| Wood Shingles and Shakes | Shingle Mills, Shakes | 2429 | The case title refers to shingle manufacturing, directly matching the Shingle Mills (Shakes) industry and its NAICS classification as sawmills. |
| Electric Shavers and Parts Thereof | Electronic Parts and Equipment, NEC | 5065 | Electric shavers are small electronic appliances, fitting best with the generic electronic parts and equipment industry. |
| Metal Castings | Nonferrous Die-Castings, Except Aluminum | 3364 | The title refers to metal casting, which aligns best with nonferrous die-casting foundries (excluding aluminum). |
| Apple Juice | Apple Orchards and Farms | 175 | Apple Juice is produced from apples, making the apple orchard industry the most directly relevant among the provided options. |
| Steel Fork Arms | Steel Foundries, NEC | 3325 | Steel fork arms are steel components manufactured by a foundry, matching the Steel Foundries, NEC industry. |
| Knives | Lawnmower Repair Shops, Sharpening and Repairing Knives, Saws and Tools | 7699 | The industry description for SIC 7699.0 lists 'Sharpening and Repairing Knives, Saws and Tools', directly matching the case title. |
| Certain Cameras | Nonclassifiable Establishments | 9999 | No candidate industry matches the keyword 'cameras'; therefore the nonclassifiable category is chosen. |
| Extruded Rubber Thread | Molded, Extruded, and Lathe-Cut Mechanical Rubber Goods | 3061 | The product is an extruded rubber thread, matching the description of Molded, Extruded, and Lathe-Cut Mechanical Rubber Goods and its NAICS counterpart for rubber products manufactured for mechanical use. |
| Fresh Winter Tomatoes | Fresh Fruits and Vegetables | 5148 | The title refers to fresh tomatoes, directly matching the Fresh Fruits and Vegetables industry and its wholesale distribution. |
| Broom Corn Brooms | Brooms and Brushes | 3991 | The title refers to manufacturing brooms, matching the Brooms and Brushes industry. |
| Fresh Tomatoes and Bell Peppers | Fresh Fruits and Vegetables | 5148 | The case title references fresh produce (tomatoes and bell peppers), matching the Fresh Fruits and Vegetables wholesaler industry. |
| Wheat Gluten | Wheat | 111 | Wheat gluten is a product derived directly from wheat, so the most appropriate industry is wheat farming. |
| Lamb Meat | Meat Markets | 5421 | The title refers to retail sale of lamb meat, matching Meat Markets. |
| Steel Wire Rod | Steel Wire Drawing | 3315 | Direct match to steel wire drawing, which produces wire rods. |
| Certain Circular Welded Carbon Quality Line Pipe | Steel Pipe and Tubes | 3317 | The product is a welded carbon-quality line pipe, which is a steel pipe manufactured from purchased steel. |
| Crabmeat from Swimming Crabs | Nonclassifiable Establishments | 9999 | No provided industry relates to seafood or crab processing, so the case falls into the nonclassifiable/unclassified category. |
| Extruded Rubber Thread | Molded, Extruded, and Lathe-Cut Mechanical Rubber Goods | 3061 | The title indicates extruded rubber threads, which are mechanical rubber goods produced by extrusion, matching SIC 3061 and NAICS 326291. |
| Steel: Determinations and Views of Commissioners | Steel Foundries, NEC | 3325 | The case concerns the steel industry in general, best aligning with steel foundry manufacturing. |
| Crystalline Silicon Photovoltaic Cells | Nonclassifiable Establishments | 9999 | No industry in the list matches photovoltaic cell manufacturing; select the nonclassifiable/unclassified category. |
| Large Residential Washers | Bolts, Nuts, Screws, Rivets, and Washers | 3452 | The only industry listed that explicitly mentions washers is Bolt, Nut, Screw, Rivet, and Washer Manufacturing, making it the closest match. |
| Fresh | Fresh Fruits and Vegetables | 5148 | The title 'Fresh' directly matches the description of Fresh Fruits and Vegetables and Fresh Fruit and Vegetable Wholesalers. |
| Fine Denier Polyester Staple Fiber | Broadwoven Fabric Mills, Manmade Fiber and Silk | 2221 | Polyester staple fiber is a manmade fiber used in broadwoven fabric manufacturing, matching the Broadwoven Fabric Mills industry. |
The Jones (1991) Model Setting Revisited
What would Jennifer J. Jones do, today?
I am not Jennifer J. Jones and (unfortunately) have never talked to her either. The following analysis is my own interpretation and adaptation of her seminal 1991 paper on earnings management using discretionary accruals. Any errors or misinterpretations are solely my responsibility. The sole purpose of this exercise is to illustrate how one might revisit and extend classic empirical accounting research using modern econometric techniques and data availability. Also, it is meant to be a fun exercise in applied econometrics. Last but not least, this is my way of learning and generating ideas for my own research. Please do not cite or circulate this work without my permission.
Empirical Strategy
Sample Selection
Matching Import Relief Investigations to Industries and Compustat Firms
I identify import relief investigations from the U.S. International Trade Commission (USITC) by scraping their Commission Publications Library. My scraping process employs robust retry logic and Cloudflare bypass mechanisms, with raw HTML cached for reproducibility and efficiency. I match investigation titles to standardized industry classifications using a SIC-NAICS crosswalk (1987/1997 versions) enhanced by semantic matching via a local language model. This procedure links (almost) each USITC investigation ID to corresponding SIC and NAICS codes, enabling systematic identification of treatment industries (those under investigation) and control industries (structurally similar but not investigated). For implementation details, see the companion Python scripts. The table below summarizes the matched import relief investigations and their corresponding industries.
- I only use safeguard investigations (not other types of import relief)
- Some investigations could not be matched to a specific SIC code (9999)
- The matching relies on LLM reasoning which may introduce errors
Accounting Data
I obtain financial statement data from Compustat North America for U.S. incorporated firms beginning in 1975. I exclude financial institutions (SIC codes 6000-6999) and require non-missing total assets for all firm-years. To ensure robust industry-specific estimation of the Jones model, I retain only industry-years (three-digit SIC level) with at least 10 observations. I exclude observations with missing values for total accruals, revenue changes, property-plant-equipment, or lagged total assets. All continuous variables are winsorized at the 1st and 99th percentiles to reduce the influence of extreme outliers. For additional implementation details, see the companion R script.
Treatment Sample Selection and Event Window Definition
To construct my treatment sample, I apply several critical filters to the matched investigations. First, I identify the investigation date and extract both the calendar year and month. To ensure that year_zero captures the last complete fiscal year before the investigation announcement, I adjust for each firm’s fiscal year-end month. Specifically, for firms with fiscal year-end months before the investigation month, their fiscal year statement would have already been reported before the investigation, making that fiscal year “year 0.” For firms with fiscal year-end months after the investigation month, their reported year 0 encompasses the investigation announcement, and I adjust their timing accordingly. Second, I address the issue of multiple investigations in the same industry. Some SIC-3 industries (314, 332, 514) experience multiple import relief investigations within short time windows. To avoid contamination and confounded treatment effects, I retain only the first investigation per SIC-3 industry, excluding subsequent treatments within the same year or immediately following year (diff_year_zero > 1). This design choice prioritizes clean identification of the initial shock at the cost of sample size—a conservative approach that trades statistical power for causal credibility.
The OG… Jones Model
Jones (1991): Time-Series Firm-Specific Approach
\[ \frac{\text{Total accruals}_{it}}{AT_{i,t-1}} = \frac{1}{AT_{i,t-1}} + \beta_1 \frac{\Delta REV_{it}}{AT_{i,t-1}} + \beta_2 \frac{PPE_{it}}{AT_{i,t-1}} + \epsilon_{it}\]
Where:
- \(\frac{\text{Total accruals}_{it}}{AT_{i,t-1}}\) = total accruals for firm i at time t
- \(AT_{i,t-1}\) = total assets for firm i at time t-1
- \(\Delta REV_{it}\) = change in revenues for firm i at time t
- \(PPE_{it}\) = property, plant, and equipment for firm i at time t
Jones (1991) estimates a separate regression for each firm using several years of historical data. The estimation period stops in year t-2. Firm-specific coefficients capture each firm’s unique accrual patterns. Compares actual accruals to the firm’s own historical norm.
Discretionary accruals: \(\text{DA}_{it}\) = residual from firm i’s time-series regression
My Approach: Cross-Sectional Industry-Specific Approach
Estimates yearly regressions by SIC-3 industry using all firms in that industry. Industry-year-specific coefficients capture industry norms in each period. Compares firm accruals to industry peers in the same year.
\(\text{DA}_{it}\) = residual from industry-year cross-sectional regression
Implication: I measure abnormal accruals relative to contemporaneous industry peers, not firm’s historical pattern
Dechow et al. (2010) reviews the literature surrounding “earnings quality,” including earnings management. They discuss trade-offs between time-series and cross-sectional approaches to measuring abnormal accruals. See Gow and Ding (2024) for an in-depth overview of implementing accrual-based earnings management measures—or for practical guidance on many aspects of empirical research in accounting.
Stacked Difference-in-Differences with First-Differenced Specification
I implement a stacked difference-in-differences (DiD) design to estimate the impact of import relief investigations on discretionary accruals. The treatment group consists of firms in industries subject to import relief investigations, while the control group includes firms in industries without such investigations (different SIC-1 codes). I define event time relative to the investigation year, with t=0 as the investigation year. For each event window (t-2 to t+2), I create a separate dataset stacking observations from treated and control industries; see, e.g., Baker et al. (2022); Baker et al. (2025) for more details on stacked DiD designs.
First-Difference DiD Model
\[\Delta \text{DA}_{it} = \beta_1Treated_i + \alpha_{fyear}+ \gamma_{cohort}+ \epsilon_{it}\]
Where:
- \(\Delta(DA_{it}) = \text{DA}_{it} - \text{DA}_{i,t-1}\) is the change in discretionary accruals for firm i at time t
- \(Treated_i\) is a binary indicator for whether firm i is in the treatment group
- \(\alpha_{fyear}\) are fixed effects for the fiscal year
- \(\gamma_{cohort}\) are fixed effects for the cohort
- \(\epsilon_{it}\) is the error term
Why?
The idea is to present results in a way that is more directly comparable to Jones (1991). She also compares changes in discretionary accruals around the investigation period, specifically in years t-1 to t+1. I want to make my results more directly comparable to hers.
Difference #1: Change in discretionary accruals within firms over time. First differencing removes firm fixed effects.
Difference #2: Difference in changes between treated and control industries over time. The coefficient on \(Treated_i\) captures the average difference in changes in discretionary accruals between treated and control industries.
Results
Summary Statistics
| Variable | N | Mean | SD | Min | 25th Pct | Median | 75th Pct | Max |
|---|---|---|---|---|---|---|---|---|
| Total Accruals | 157866 | -0.05 | 0.22 | -2.53 | -0.09 | -0.04 | 0.00 | 1.19 |
| Discretionary Accruals | 157866 | 0.01 | 0.19 | -2.61 | -0.04 | 0.00 | 0.05 | 2.77 |
| Total Assets | 157866 | 1843.36 | 9560.28 | 0.00 | 19.27 | 114.32 | 815.61 | 551669.00 |
| Inverse Lagged Total Assets | 157866 | 0.14 | 0.61 | 0.00 | 0.00 | 0.01 | 0.06 | 8.00 |
| Change in Revenues | 157866 | 0.14 | 0.41 | -1.17 | 0.00 | 0.07 | 0.23 | 2.99 |
| Property, Plant, and Equipment | 157866 | 0.78 | 0.52 | 0.00 | 0.37 | 0.71 | 1.15 | 3.14 |
| Treated Indicator | 157866 | 0.01 | 0.11 | 0.00 | 0.00 | 0.00 | 0.00 | 1.00 |
| Time Relative to Investigation | 157866 | -0.03 | 1.99 | -3.00 | -2.00 | 0.00 | 2.00 | 3.00 |
| Fiscal Year | 157866 | 1989.79 | 11.42 | 1976.00 | 1981.00 | 1986.00 | 1997.00 | 2023.00 |
First-Difference DiD Estimates
The table and figure below present the results of the first-difference DiD estimation. The table shows the estimated treatment effects for each time window around the import relief investigations, while the figure plots the coefficients for each estimation window to visualize the dynamics of changes in discretionary accruals between treated and control industries for each time window.
First-Difference DiD Estimates of Changes in Jones Residuals Around Import Relief Investigations
Event-study: Difference-in-Differences Estimates of Jones Residuals Around Import Relief Investigations
Limitations
What about other (real) earnings management measures?
Typically, one would like to see results using multiple measures of earnings management; see, e.g., Dechow et al. (2010) for an overview - Typically, one would like to see results using multiple measures of earnings management, see e.g. Dechow et al. (2010) fot an overview - Breuer and Schütt (2023) provides a Bayesian framework to combine multiple earnings management measures into a single latent construct - To go even further, one could consider real earnings management measures as in Roychowdhury (2006) (better leave that up to Reviewer 2 to decide for you…) - While you are at it, also check and apply Srivastava (2019) for improved measurement of real earnings management (I see you, Reviewer 2…)
Residuals as Dependent Variable
- Discretionary accruals are estimated residuals from the Jones model (two-step approach)
- Chen et al. (2018) and B. Chen et al. (2023) highlight potential bias and inefficiency in two-step approaches
- Solution: Use control function or joint estimation methods
- I am not giving this a separate headline, but make sure your standard errors game is on par with the latest literature (e.g., W. Chen et al. (2023) or Abadie et al. (2023)), in case Reviewer 2 asks you about it…
Statistical Power
- Effect is statistically significant (p < 0.05) in one period—where we would expect it (\(t=0\)) to be strongest
- Not statistically significant in other periods
- Standard errors are clustered at the cohort-gvkey level—may be conservative but necessary to account for within-firm and within-cohort correlation (I see you, Reviewer 2…)
Economic Magnitude
- Effect size (2.0 pp) is approximately 1/3 of Jones’s finding
- Could reflect: (1) fiscal year dilution, (2) industry aggregation, (3) control group contamination, (4) measurement error in cross-sectional DA models
Control Group Validity
- Control industries (different SIC-1) may still face import competition
- Could attenuate treatment effect if controls also manipulate
- Parallel trends are validated in the pre-period, but the assumption may not hold throughout
Conclusion
The findings provide evidence consistent with Jones (1991) using a complementary identification strategy. The stacked DiD with cross-sectional discretionary accruals and contemporaneous industry controls offers:
- Stronger causal identification through parallel trends validation
- Robustness to systematic time-period effects
- Industry-level confirmation of firm-level manipulation documented by Jones