Is the InterNet killing cultural expression? III

How about TV shows? This chart shows new US TV shows introduced, 1960-2016 (Fig 4.1  [1]):

How do we know that greater number of TV shows is not killing quality? That's discussed in the next post, Is the InterNet killing cultural expression? IV

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References

[1]  Joel Waldfogel's Digital Reinassance. Princeton: Princeton Univ Press, 2018.