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result is consistent with the research of Law, S. H. et al. (2020), Pham, T.C (2025). In the
short term, the interaction between FDI and GDP is inverse because from investment to
the production of goods and services, there are always certain delays. Meanwhile,
innovation is not statistically significant due to delays in the research, application and
commercialization of creative results. Overall, these results show that in the short term,
Vietnam's EG is mainly influenced by traditional factors such as labor, while the role of FDI
and innovation needs time to become more pronounced.
4.5. Diagnostic testing
- Testing the stability of model:
The results of testing the stability of the model show that the values are all in a
circle. This shows that the short-term impact analysis model is stable and reliable.

Figure 2. Inverse Roots of AR Characteristic Polynomial
Source: Research results from Eview 10
- Autocorrelatons testing
Table 8. Portmanteau Tests

Lags Q-Stat Prob.* Adj Q-Stat Prob.* df

1 8.723958 --- 9.087457 --- ---
2 19.43673 --- 20.73177 --- ---
3 32.35905 0.2601 35.41623 0.1581 28

Source: Results extracted from Eviews software
The Portmanteau Tests results had no autocorrelation in the model with a
statistically significant level of 1%.
- Residual Tests:

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