Antonio Praticò To investigate the impact of internal M&A teams in M&A transactions, you could use a comparative analysis approach. You could compare the performance of M&A transactions led by internal M&A teams against those led by external advisors. You could use the metrics you mentioned, such as shareholder value creation, long-term stock returns, changes in long-term operating results, and changes in analysts' earnings forecasts to compare the performance of these transactions. This would help you identify if there is a significant difference in the performance of transactions led by internal M&A teams compared to those led by external advisors.

Investigating the impact of internal M&A teams on mergers and acquisitions transactions requires a comprehensive analysis that considers multiple factors and perspectives. While there is no single "best" analytical approach, a combination of qualitative and quantitative methods can provide valuable insights. Here are some steps you might consider:

1. Define research objectives: Clearly state the specific aspects of the impact of the internal M&A team that you wish to examine. For example, you might want to analyze their role in transaction sourcing, due diligence, integration planning, or post-merger performance.

2. Collect data: Collect relevant data about M&A transactions involving internal teams. This may include financial reports, agreement documentation, organizational structure, team composition, performance metrics, and available internal or external evaluations of M&A results.

3. Conduct interviews or surveys: Involve key stakeholders, such as M&A team members, executives, employees, and external advisors. Qualitative interviews or surveys can help gather insight into team effectiveness, decision-making processes, collaboration with other departments, and overall contribution to handling success.

4. Analyze financial performance: Quantitatively assess the financial impact of M&A transactions involving internal teams. Compare key financial metrics (e.g. revenue growth, profitability, shareholder value) before and after transactions. Perform statistical analysis, such as a regression model, to isolate the impact of the M&A team from other factors that may impact performance.

5. Assess integration success: Evaluate the effectiveness of the post-merger integration efforts led by the internal team. Measure achievement of integration milestones, cultural alignment, employee satisfaction, and realized potential synergies. Use qualitative and quantitative data to measure integration results.

6. Benchmark against industry peers: Compare the performance of M&A transactions involving internal teams with similar deals in the industry. Take advantage of industry-specific benchmarks or performance indices to assess the relative effectiveness of teams.

7. Identify lessons learned and best practices: Based on your analysis, identify patterns, success factors, and challenges related to the impact of the internal M&A team. Extract lessons learned and best practices that can guide future M&A activities.

8. Consider limitations and alternative explanations: Acknowledge the limitations of your analysis, such as potential confounding variables or bias. Consider alternative explanations for the observed results to ensure a comprehensive understanding of the M&A team's impact.

Merger and acquisition transaction is the total cost of Merger and acquisition. Then the internal Merger and acquisition team is the value added by the team.

For internal Merger and acquisition value, you can use questionnaire method if this value is qualitative incase. It will help you to quantify the value of the team impact.

Then total cost of Merger and acquisition = Merger and acquisition transaction

Comparative analysis is suitable technique to investigate the impact of merger and acquisition. The internal manager of Merger and acquisition has to consider certain financial parameters which are sales, gross profit, EBITDA, NET income and the like parameters as well as advice of external experts.

You can explore the relationship between your chosen variable in this context through using structural equation modelling (SEM) methodology.