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Firm-Level Finance & Panel Econometrics2016–2024 panel · Completed econometric analysis

Operating Synergy and Profitability in Vietnamese Listed Firms

Poster summary

Stata · firm fixed effects · Driscoll–Kraay · System GMM · marginal effects

A completed panel-econometric analysis of whether gross margin and asset turnover jointly explain return on assets beyond their separate contributions.

01

Research question

Is the interaction between gross margin and asset turnover associated with higher profitability after controlling for firm characteristics, dynamics, and common year shocks?

02

Methodology

Pooled OLS, fixed effects, random effects, Driscoll–Kraay fixed effects, dynamic System GMM, model-selection tests, and marginal effects

03

Dataset

Vietnamese listed-firm accounting panel with 662 source firm-years and 385 observations in the common reported model table, primarily 2016–2024

04

Main finding

The gross-margin × asset-turnover interaction is positive across OLS, FE, RE, Driscoll–Kraay FE, and System GMM, ranging from 0.276 to 0.645 in the reported table.

Operating Synergy and Profitability in Vietnamese Listed Firms

Overview

This project examines whether profitability reflects the joint operation of pricing or margin discipline and asset-use efficiency. The analysis treats the interaction between gross margin and asset turnover as the focal empirical quantity.

Research Question

Is the gross-margin × asset-turnover interaction positively associated with return on assets after accounting for persistence, capital structure, cash generation, firm effects, and year shocks?

Economic or Technical Motivation

Margin and turnover can be operational complements: a firm that earns more on each sales unit and generates more sales per asset unit may achieve a profitability gain beyond either component alone.

Data

The source ratio panel contains 662 Vietnamese listed-firm-year rows. After applying model variables and lags, the common comparison table reports 385 observations, primarily over 2016–2024. Variables include ROA, gross margin, asset turnover, debt, cash flow, retained earnings, and asset growth.

Methodology

The workflow compares clustered pooled OLS, firm fixed effects, random effects, Driscoll–Kraay fixed effects, and two-step System GMM. It includes model-selection tests, heteroskedasticity, serial-correlation and cross-sectional-dependence diagnostics, year effects, and marginal-effect calculations.

Main Findings

The interaction coefficient is positive in every reported estimator: 0.276 in OLS, 0.645 in fixed effects, 0.294 in random effects, 0.645 with Driscoll–Kraay inference, and 0.349 in System GMM. Each is marked significant at the 1% level in the archived table. The FE adjusted R-squared is 0.786.

Robustness, Validation, or Model Assessment

The positive interaction is stable across estimators with different assumptions. The code also runs Hausman, heteroskedasticity, autocorrelation, and cross-sectional-dependence diagnostics. The exported summary does not preserve the full System GMM AR and Hansen diagnostics, so the GMM estimate is supporting evidence rather than the basis for identification.

Tools and Technologies

Stata, firm fixed effects, clustered standard errors, Driscoll–Kraay inference, System GMM, and marginal-effects analysis are directly demonstrated.

Limitations

The interaction is associational and may reflect unobserved operating strategy. The estimation sample is much smaller than the source panel, and the archived table does not include complete GMM validity diagnostics.

Deliverables

  • Constructed firm-ratio panel
  • Full Stata diagnostic and estimation script
  • Five-estimator comparison table
  • Marginal-effect specifications