The technology revolution has delivered Google searches, Facebook friends, iPhone apps, Twitter rants and shopping for almost anything on Amazon, all in the past decade and a half.

What it hasn’t delivered are many jobs. Google’s Alphabet Inc. and Facebook Inc. had at the end of last year a total of 74,505 employees, about one-third fewer than Microsoft Corp. even though their combined stock-market value is twice as big. Photo-sharing service Instagram had 13 employees when it was acquired for $1 billion by Facebook in 2012.

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