• Shares can be bought and sold without dealing costs – unrealistic, but doubtful if this makes a significant difference.
• Capital markets are efficient – seems reasonable.
• Interest rates are equal between borrowing and lending, businesses and individuals – obviously invalid.
  Large businesses in particular can borrow large amounts at very competitive rates, but doesn’t invalidate MM’s argument.
• There are no bankruptcy costs – invalid, but not important in the broad argument if gearing costs are moderate as bankruptcy is unlikely.
• Two businesses are identical apart from gearing – This is not true, but not necessary for the proposition to be valid.
• There is no taxation -- this is invalid and MM had to reconsider their argument.

MM assumptions on dividends

• There are frictionless capital markets (no costs involved in decisions) – Invalid as there are dealing costs as homemade dividends or dividend cancellation involve dealing costs.
• Securities are efficiently priced in the capital market – valid on the weak form and semi-strong form efficiency.
• Shares may be issued by businesses without any legal or administrative costs – not valid.
  
• Taxes do not exist – not true

business -- not affected by dividends;

shareholders – is it more tax efficient to receive dividends or make capital gains?

• Some deficiencies weaken M&M's view, but do not sufficiently profound to destroy it.