Reading an M&A Accretion/Dilution Model

Accretion/dilution analysis answers a narrow question: after an acquisition closes, does the combined company's earnings per share go up or down relative to the acquirer's standalone EPS? Mechanically it is arithmetic. The useful interview skill is naming the driver: target earnings yield versus the cost of the funding mix.

The short answer

"A deal is accretive when pro forma EPS rises versus the acquirer's standalone EPS. That usually happens when the earnings you buy, after synergies and after the after-tax cost of new debt, more than offset the dilution from new shares. Cash/debt funding is often more accretive than stock at a rich valuation, holding price constant. Accretion is not the same as value creation."

Building the pro forma numbers

Purchase Equity Value = Offer Price per Share x Target Shares Outstanding
Cash Consideration = Purchase Equity Value x % Cash
Stock Consideration = Purchase Equity Value - Cash Consideration
New Shares Issued = Stock Consideration / Acquirer Share Price

The acquirer funds with some mix of cash (often debt-funded) and stock. Cash funded by new debt costs the after-tax interest rate. Stock costs the acquirer's earnings yield in the sense that new shares claim the combined earnings pool.

Pro forma net income and EPS

Pro Forma Net Income = Acquirer NI + Target NI + Pre-Tax Synergies x (1 - Tax Rate)
                        - (Cash Consideration x Cost of Debt) x (1 - Tax Rate)

Pro Forma EPS = Pro Forma Net Income / (Acquirer Shares + New Shares Issued)

Combined NI adds both companies' earnings, adds tax-effected synergies, and subtracts after-tax interest on new debt for the cash portion. Stock has no interest line, but it hits the denominator as more shares.

Accretion / (Dilution) % = Pro Forma EPS / Acquirer Standalone EPS - 1

The actual driver: earnings yield vs cost of funding

Here is the intuition that makes this click: a deal is accretive when the target's earnings yield (roughly Net Income / Purchase Price, the inverse of the P/E paid) is higher than the acquirer's cost of the funding source used. If you buy earnings more cheaply in yield terms than it costs to fund them, EPS goes up. If you overpay relative to funding cost, EPS goes down even if the target is a good business.

That is why the same deal can be accretive funded one way and dilutive funded another. Debt is often "cheaper" in this narrow EPS sense than issuing stock at a rich valuation, which is why cash/debt-funded deals are more commonly accretive than all-stock deals, holding the target and price constant.

Funding as strategy, not only an EPS lever

Funding with cash and debt avoids diluting ownership percentage but increases financial risk and requires borrowing capacity. Funding with stock aligns target shareholders as owners of the combined company (useful when you want continued management alignment or shared integration risk), but dilutes existing holders and can signal that management thinks its stock is rich. Real deals often use a mix to balance accretion, leverage, and signaling, not to maximize EPS alone.

What "accretive" does not tell you

Accretion/dilution is a near-term EPS effect. It does not prove economic value creation, strategic fit, or that synergies will show up. A deal can be immediately accretive and still be a bad deal if synergies miss or the acquirer overpays versus long-run cash flows. A deal can be dilutive near term and still create value if the strategic logic and FCF trajectory are strong.

Common interview traps

1. Saying all-cash deals are always better without mentioning leverage risk
2. Forgetting tax on interest and on synergies
3. Using basic shares for the target when the offer is on fully diluted shares
4. Ignoring purchase accounting amortization that can hit EPS after close
5. Treating accretion as proof the deal creates shareholder value

Mechanics walkthrough

Verbal 30 seconds

"Accretion/dilution asks whether pro forma EPS rises or falls. I combine net income, add tax-effected synergies, subtract after-tax interest on new debt, and divide by acquirer shares plus new shares issued. Economically, you compare the earnings yield you buy with the cost of the funding mix. Accretive does not automatically mean value-creating."

Related

Pair with Cash vs Stock M&A, Break-Even Synergies, Control Premium, and Treasury Stock Method for the diluted share count on both sides.