What does the author define as “Silicon Valley”? Northern California has expanded “Silicon Valley” to far beyond the Santa Clara Valley origination. That entire premise is just far fetched that Sweden has surpassed it. Percentage wise, perhaps. Sheer numbers, no way.
“Silicon Valley is the southern part of the San Francisco Bay Area in Northern California in the United States...Some notable tech companies headquartered in the South Bay are Intel, AMD, Cisco Systems, Hewlett-Packard, Apple, Google, eBay,and Yahoo!.”
In terms of producing advanced high tech solutions I think it’s safe to say a large number of companies based in Stockholm (or at least having a lot of employees there) can compete. Examples are Ericsson, ABB, Electrolux, Astra-Zeneca, Atlas Copco, SAAB, Tieto Enator, Scania, Telia-Sonera, WM-data.
These examples are Swedish or ‘part’ Swedish ones (for instance, a company like ABB is the result of a Swedish-Swiss merger and Astra-Zeneca of a Swedish-British dito).
‘Foreign’ high-tech companies with a lot of staff in the greater Stockholm area include GE healthcare, Pfizer, Microsoft, IBM and Cap Gemini.
One thing that ought to be remembered here is that an extremely large percentage of the Swedish workforce has advanced university education and are employed by large companies that often are very technology- and research- intensive. A country like Germany also possesses a highly skilled workforce, but the business life of Germany is not as dominated by such multinationals as its Swedish counterpart (even if Germany has a larger population and all that).