Dupont analysis is used to compare the financial performance of Pfizer Inc. in the year before the CEO turnover in 2018 (year t-1), and the year after (year t+2). Key metrics like return on equity, asset turnover, and profit margin are calculated from financial statements filed with the SEC to evaluate how the CEO change impacted Pfizer's profitability by decomposing return on equity. Noncontrolling interests are excluded from ratio calculations.