I stumbled upon a case about baby helmets (L.E.K) that states that two dominant players have together 60% market share. Later, we need to calculate the total market profit and then have to figure out the market share that we need to achieve given our profit goal. They calculate it simply by dividing our profit goal by the total market profit.
Hence, the implicit assumption is that prices and costs per unit are the same for every player in the market? Otherwise we couldn't calculate this using the profits as market share is based on revenue and not profit right?