Only 52 US companies are in Fortune 500 list since 1955

Would be more interesting/honest if they differentiated between companies that have declined versus just mergers.

The AEI is making the point there is more creative destruction than people think - which is fair.

But Mobil is counted as if it isn't in the top 500 companies now because it merged. But it wasn't just gobbled up - if it was independent it would clearly be top 500 still. If you were a shareholder in 1955 you'd be pleased.