What is accretion / dilution analysis, and why is it the most important output of an M&A model?

Accretion / dilution analysis measures whether a transaction increases or decreases the acquirer's EPS after the deal. It is a core public-company M&A output because boards and investors focus on EPS impact, financing mix, synergies, and timing. Accretive means combined EPS is higher than standalone EPS; dilutive means lower. It is important, but it is not the same as value creation.