Further analysis of 65 companies on the list of 87 (it was too boring to finish everything) finds 161 founders, for an estimated founder population of about 215.5.

You'll notice that the report doesn't come out and give the number of immigrant founders. Summing up table 3 gives 61, and 61/215.5 => 28% .

This is indeed higher than the 13% of the US population who are immigrants, though not as eye-catching of a number as 51%.

Part of the argument for immigrant co-founders is the increased diversity. For example, "Michelle believes the diverse backgrounds of CloudFlare’s founders has contributed to the company’s success." If that is an important criteria, then you should note that some of the companies only have immigrant founders, which by that logic should count against them.

I'm not sure how to judge a U.S. company where one of the founders lives overseas. For example, Oded Comay of ForeScout appears to live in Israel. I don't know which of the founders are non-American and also non-immigrants.

Unlike the report, I'll give my list of companies (from the same WSJ source, though I have one more company than the report does) and my attempt at finding the number of founders for each company. I assert that not giving that data makes it harder to understand, much less replicate, the significance of the results.

Uber - (2) Travis Kalanick, Garrett Camp
Airbnb - (3) Joe Gebbia, Nathan Blecharczyk, Brian Chesky
Palantir - (5) Peter Thiel, Joe Lonsdale, Alex Karp, Stephen Cohen, Nathan Gettings
Snapchat - (2) Evan Spiegel, Bobby Murphy, (and Frank Reginald "Reggie" Brown IV?)
SpaceX - (1) Elon Musk
Pinterest - (3) Paul Sciarra, Evan Sharp, Ben Silbermann
Dropbox - (2) Arash Ferdowsi, Drew Houston
WeWork - (2) Adam Neumann, Miguel McKelvey
Theranos - (1) Elizabeth Holmes
Lyft - (2) Logan Green, John Zimmer
Stripe - (2) Patrick Collison, John Collison
Stemcentrx - (3) Brian Slingerland, Scott Dylla, Daniel T. Reiner
Zenefits (YourPeople) - (2) Parker Conrad, Laks Srini
Cloudera - (4) Jeff Hammerbacher, Mike Olson, Amr Awadallah, Christophe Bisciglia
SoFi (Social Finance) - (4) Mike Cagney, Dan Macklin, James Finnigan, and Ian Brady
Credit Karma - (1) Kenneth Lin
Tanium - (2) David Hindawi, Orion Hindawi
Fanatics - (1) Alan Trager
DocuSign - (1) Tom Gonser
Moderna - (4) Robert Langer, Noubar Afeyan, Ken Chien, Derrick Rossi
Wish (ContextLogic) - (2) Peter Szulczewski, Danny Zhang
Bloom Energy - (1) K. R. Sridhar
Slack - (4) Stewart Butterfield, Eric Costello, Cal Henderson, and Serguei Mourachov
Mozido - (1) Michael A. Liberty
Houzz - (2) Adi Tatarko, Alon Cohen
DraftKings - (3) Jason Robins, Matt Kalish, Paul Liberman
Nutanix - (3) Dheeraj Pandey, Mohit Aron, Ajeet Singh
Magic Leap - (1) Rony Abovitz
Instacart
Domo
Blue Apron
Github
Avant
AppDynamics
Prosper Marketplace
ZocDoc
AppNexus
Intarcia Therapeutics
Honest Co.
Oscar Health Insurance
MongoDB
Jawbone
InsideSales.com
MuleSoft
BuzzFeed - (2) Jonah Peretti, John Johnson
Mu Sigma - (1) Ambika Dhiraj
Jasper Technologies - (3) Jahangir Mohammed, Daniel Collins, Amit Gupta
Deem - (1) Patrick Grady
Jet.com - (3) Marc Lore, Nate Faust, Mike Hanrahan
Thumbtack - (4) Marco Zappacosta, Sander Daniels, Jonathan Swanson, Jeremy Tunnell
FanDuel - (5) Nigel Eccles, Lesley Eccles, Tom Griffiths, Rob Jones, Chris Stafford
Medallia - (2) Borge Hald, Amy Pressman
Infinidat - (1) Moshe Yanai
Warby Parker - (4) David Gilboa, Neil Blumenthal, Andrew Hunt, Jeffrey Raider
Okta - (2) Todd McKinnon, Frederic Kerrest
Sprinklr - (1) Ragy Thomas
Automattic - (1) Matt Mullenweg
Actifio - (1) Ash Ashutosh
Proteus Digital Health - (3) Andrew Thompson, George Savage, Mark Zdeblick
Nextdoor - (4) Nirav Tolia, Sarah Leary, Prakash Janakiraman, David Wiesen
Uptake - (2) Eric Lefkofsky, Brad Keywell
Anaplan - (2) Guy Haddleton, Michael Gould
Gusto (ZenPayroll)
AppDirect
23andMe
CloudFlare
Evernote
Eventbrite
Tango
Kabam
Lookout
JustFab
Qualtrics
Razer
SimpliVity
Pluralsight
MarkLogic
Coupa Software
Twilio
Zscaler
Vox Media
Adaptive Biotechnologies
Apttus
Kabbage
Datto
Udacity
Docker
Mode Media - (9) Samir Arora, Ernie Cicogna, Fernando Ruarte, Vic Zauderer, Dianna Mullins, Raj Narayan, Rebecca Bogle Arora, Susan Kare, Emmanuel Job
ForeScout - (4) Oded Comay, Dror Comay, Doron Shikmoni, Hezy Yeshurun
Fab - (2) Jason Goldberg, Bradford Shellhammer
Gilt Groupe - (6) Kevin P. Ryan, Dwight Merriman, Alexis Maybank, Alexandra Wilkis Wilson, Michael Bryzek, Phong Nguyen
Good Technology - (1) Richard Davies
Legendary Entertainment - (1) Thomas Tull
Pure Storage - (2) John Colgrove, John Hayes
Square - (2) Jack Dorsey, Jim McKelvey
Sunrun - (3) Lynn Jurich, Edward Fenster, Nat Kreamer
Beats Electronics - (2) Dr. Dre, Jimmy Iovine
Box - (4) Aaron Levie, Dylan Smith, Sam Ghods, Jeff Queisser
Coupons.com - (1) Steven Boal
Fisker Automotive - (2) Henrik Fisker, Bernhard Koehler
GoPro - (1) Nicholas Woodman
Hortonworks - (8) Alan Gates, Arun C. Murthy, Devaraj Das, Eric Baldeschwieler, Mahadev Konar, Owen O'Malley, Sanjay Radia, Suresh Srinivas
Lending Club - (2) Renaud Laplanch, Soulaiman Htite
Nest Labs - (2) Tony Fadell, Matt Rogers
New Relic - (1) Lewis Cirne
Wayfair - (2) Niraj Shah, Steve Conine