安全與新興技術中心：2022國際STEM博士畢業生的長期留任率（英文版）（20頁）.pdf

1、 April 2022 The Long-Term Stay Rates of International STEM PhD Graduates CSET Issue Brief AUTHORS Jack Corrigan James Dunham Remco Zwetsloot Center for Security and Emerging Technology|1 Executive Summary This issue brief examines how many international STEM PhD graduates choose to stay in the Unite

2、d States after earning their degrees and explores how those graduates navigate the U.S.immigration system.Our analysis is based on data collected through the National Science Foundations(NSF)Survey of Doctorate Recipients(SDR),a survey that collects information on the demographics and employment tre

3、nds of PhD graduates from U.S.universities(see Box 1 for details).We found that a large majority of foreign nationals who earn STEM PhDs in the United States remain in the country many years after graduating.Specifically,we found that:1.Long-term stay rates are high.As of February 2017,roughly 77 pe

4、rcent of the more than 178,000 international STEM PhD graduates from U.S.universities between 2000 and 2015 were still living in the country.2.Stay rates remain high even among older graduates.Since 2000,at least 65 percent of every years graduating class has stayed in the United States,and since 20

5、04,no graduating class has had a stay rate below 73 percent.3.Stay rates are similar across STEM fields.Though stay rates for different fields vary across individual years,no one STEM discipline has consistently higher or lower stay rates than the others.4.Chinese and Indian nationals account for ne

6、arly half of all international STEM PhD graduates in the United States,and most stay long after graduation.In February 2017,approximately 90 percent of Chinese nationals and 87 percent of Indian nationals who completed STEM PhD programs in the United States between 2000 and 2015 were still living in

7、 the country,compared to 66 percent of graduates from other countries.Due to country caps on green cards,Indian graduates have more difficulty obtaining permanent residency than other international students.5.International STEM PhD graduates follow a similar path through the U.S.immigration system.T

8、he plurality of graduates who completed their degrees between 2004 and 2011 had obtained permanent residency by February 2017,and among those who graduated before 2004,nearly half had become naturalized U.S.citizens.Center for Security and Emerging Technology|2 Box 1.National Science Foundation Surv

9、ey Data Our analysis relies on data from the NSFs SDR,a biennial panel survey that collects information on the demographics and employment trends of PhD graduates from U.S.universities.The survey includes PhD graduates who hold a research doctorate in a science,engineering,or health-related field.We

10、 use data from the 2017 survey,which was administered to a sample of 124,580 PhD graduates who earned their degrees prior to July 1,2015.Survey respondents described their immigration status as of early February 2017.1 Initially,we analyzed the stay rates of international STEM PhD graduates using da

11、ta from the 2019 SDR.We decided to use the 2017 SDR instead after NSF warned of possible bias in estimates of stay rates based on 2019 data,due to higher rates of nonresponse among PhD graduates who lived outside the United States.*Our analysis of the 2019 data found virtually no change in overall s

12、tay-rate trends between the two surveys(e.g.,the stay rate for all international STEM PhD graduates was roughly 77 percent in both the 2017 and 2019 SDR).Still,given the potential issues in the 2019 survey,we cannot definitively conclude that trends remained the same.We hope to reexamine stay-rate t

13、rends with greater certainty using the forthcoming 2021 SDR.SDR data is not publicly available due to privacy considerations.Researchers can request access to the data through an NSF license request.The use of NSF data does not imply NSF endorsement of the research,research methods,or conclusions co

14、ntained in this report.*Specifically,the NSF recommended that researchers“exercise caution when conducting any small domain analysis and estimation as the potential nonresponse bias may be non-ignorable at small domain levels such as country of origin.”In other words,this bias would prevent us from

15、obtaining reliable estimates on the stay rates of students from individual countries,such as China and India.Center for Security and Emerging Technology|3 How Long Do International STEM PhD Graduates Stay in the United States?One of the United States greatest advantages in attracting STEM talent is

16、the strength of its higher education system.U.S.universities remain a top destination for students around the world,particularly at the graduate level.2 International students accounted for more than 40 percent of the roughly 500,000 doctoral degrees awarded by U.S.universities between 2000 and 2019

17、.3 Those who stay in the country after receiving their degrees strengthen the domestic STEM workforce and make valuable contributions to the economy and society.4 As shown in Figure 1,the large majority of international students who earn their PhDs from U.S.universities stay in the country for many

18、years after graduation.As of February 2017,approximately 77 percent of international STEM PhD holders who graduated between 2000 and 2015 were still living in the United States.Since 2000,at least 65 percent of every years graduating class has stayed in the United States,and since 2004,no graduating

19、 class has had a stay rate below 73 percent.Generally,stay rates have fluctuated with the health of the U.S.economy.Graduates left the country at higher rates immediately following the dot-com crash in 20002001 and the Great Recession in the late-2000s.In both cases,stay rates rose back up as the ec

20、onomy recovered.Center for Security and Emerging Technology|4 Figure 1.Stay Rates of International STEM PhD Graduates Source:2017 NSF Survey of Doctorate Recipients(see Appendix A).*Stay rates among international PhD graduates are similar across STEM disciplines.Table 1 shows the stay rates among Ph

21、D graduates in different academic fields.Though rates vary across fields in individual years,no one STEM discipline has consistently higher or lower stay rates than the others.Overall,international STEM PhD graduates are much more likely to remain in the United States after graduation than those who

22、 earn PhDs in non-STEM fields.Between 2000 and 2015,the stay rate for international PhD graduates who did not study STEM was approximately 55 percent,compared to 77 percent among STEM graduates.The remainder of this paper focuses specifically on STEM PhD graduates.5 *It is important to note the data

23、 referenced in Figure 1 and throughout the rest of this brief does not reflect the immigration patterns of a single group of individuals over time.Rather,it provides a snapshot of the immigration status of different graduate cohorts as of February 2017,unless otherwise specified.Center for Security

24、and Emerging Technology|5 Table 1.Stay Rates of International PhD Graduates as of February 2017 by Field Field Graduation Cohort 20002003 20042007 20082011 20122015 All Years STEM 73%75%76%81%77%CS/Math 68%77%75%82%76%Engineering 75%79%78%82%79%Life Sciences 69%73%78%81%76%Physical Sciences 78%71%71

25、%77%74%Non-STEM 52%53%57%58%55%All(STEM+Non-STEM)69%72%74%78%74%Source:2017 NSF Survey of Doctorate Recipients.Stay rates also varied significantly based on graduates nationalities,as shown in Figure 2.For example,Chinese and Indian nationals were far more likely to stay in the United States after g

26、raduation than other international graduates.As of February 2017,about 90 percent of Chinese nationals and 87 percent of Indian nationals who earned STEM PhDs between 2000 and 2015 were still living in the United States,compared to just 66 percent of graduates from other countries.The data also sugg

27、ests that of the Chinese and Indian graduates who leave the United States,most do so immediately after graduation,while other international students are more likely to trickle out of the country over time.Center for Security and Emerging Technology|6 Figure 2.Stay Rates of Chinese,Indian,and Other I

28、nternational STEM PhD Graduates as of February 2017 Source:2017 NSF Survey of Doctorate Recipients(see Appendix B for more detailed data).Prior research suggests there are three major categories of factors that affect international graduate students decisions to stay or leave the country where they

29、obtained their degree:professional opportunities,immigration rules,and personal and cultural considerations.Graduates are more likely to stay when immigration restrictions are lower and when they have fewer job prospects and social ties in their home country.6 How International STEM PhD Graduates Mo

30、ve Through the U.S.Immigration System Most foreign graduate students who attend U.S.universities enter the country under F-1 student visas.These visas generally authorize students to remain in the country for the duration of their studies.The subsequent immigration process for international graduate

31、 students typically includes some combination of the following steps:Center for Security and Emerging Technology|7 temporary residency(e.g.,an H-1B visa),permanent residency(i.e.,a“green card”),and ultimately citizenship through naturalization.Box 2 explains each of these steps in greater detail.Box

32、 2.Understanding the Immigration System After graduation,people who hold F-1 student visas can take a number of different paths through the U.S.immigration system.All graduates who hold F-1 visas are eligible for a period of Optional Practical Training,which permits them to work on a full-time basis

33、 in the United States while retaining their F-1 student visa status.STEM graduates may take up to three years of OPT while non-STEM graduates are only eligible for one year.7 After finishing their studies or expending their OPT,graduates can apply for a different temporary work visa or,in some cases

34、,permanent residency.Graduates can obtain temporary residency if their employer is willing to sponsor them for a“non-immigrant”work visa.The most common of these authorizations is the H-1B visa.H-1Bs are typically valid for three years,with an option to extend for one additional three-year period.8

35、Other types of non-immigrant work visas existsuch as L-1 visas and J-1 visasthough they are not commonly used by former international graduate students.9 Employers can also sponsor international students and non-immigrant workers for permanent residency,otherwise known as green cards.10 Green cards

36、are awarded on a first-come-first-serve basis,with caps on the proportion of visas that can go to applicants from a single country.These caps have created extensive backlogs for applicants from certain populous countries,like China and India.Permanent residents can begin the naturalization process a

37、fter holding a green card for three or five years.However,some forgo the naturalization process and instead choose to remain in the United States by renewing their green cards every 10 years.From an employment perspective,the main benefit of citizenship is that it opens the door to defense-and gover

38、nment-related jobs that otherwise exclude non-U.S.citizens.Center for Security and Emerging Technology|8 This progression through the U.S.immigration system is depicted in Figure 3,which shows the immigration status of different cohorts of international STEM PhD graduates.In general,the more time th

39、at has passed since an individual earned their degree,the further along they are in the immigration process.For the first few years after earning their doctorate,international STEM PhD graduates are most likely to live as temporary residents.A plurality of foreign nationals who graduated six to 13 y

40、ears before February 2017 had obtained green cards,and a plurality of those who graduated 14 or more years before had become naturalized citizens.Of the roughly 80,000 international students who earned STEM PhDs from U.S.universities between 2000 and 2007,approximately 56,000(70 percent)had become p

41、ermanent residents or naturalized citizens by February 2017.Figure 3.Immigration Status of International STEM PhD Graduates as of February 2017 Source:2017 NSF Survey of Doctorate Recipients(see Appendix C for detailed data).11 However,some graduates have a harder time putting down roots in the Unit

42、ed States than others.While international students generally compete on a level playing field when applying for student visas and temporary residency,their ability to secure permanent residency is heavily influenced by their nationality.Center for Security and Emerging Technology|9 Under current imm

43、igration laws,no more than 7 percent of green cards awarded in a given year can go to individuals from any single country.12 These“country-based caps”create lengthy backlogs for people coming from populous countries with large numbers of applicants,most notably China and India.One study projected th

44、at a Chinese national who applied for EB-2 or EB-3 permanent residency in 2020 would need to wait more than a decade to have their application processed.For Indian nationals,the expected wait time was upwards of 80 years.13 U.S.policymakers have recently sought to streamline this choke point in the

45、immigration systemin February 2022,the U.S.House of Representatives approved a measure that would exempt STEM PhD holders from country-based green card caps.14 However,as of the publication of this brief,it is unclear whether the measure will be enacted into law.The remainder of this section takes a

46、 closer look at Chinese and Indian nationals who obtain STEM PhDs from U.S.universities and explores how their journey through the immigration system compares to other international PhD graduates.Chinese and Indian students accounted for nearly half of the international STEM PhD graduates in the Uni

47、ted States between 2000 and 2015,and the vast majority stay in the United States after earning their degrees.15 China More than 55,000 Chinese nationals graduated from STEM PhD programs at U.S.universities between 2000 and 2015,accounting for nearly one-third of all international graduates.As of Feb

48、ruary 2017,about 50,000 of those graduates(90 percent)still lived in the United States.As shown in Figure 4,Chinese STEM PhD graduates have generally followed the same path through the immigration system as other international graduates.Most Chinese nationals stayed in the United States as temporary

49、 residents in the years immediately following graduation,but very few relied on temporary visas to stay in the country over the long term.A majority of Chinese nationals secured green cards within about six years of graduation,and most ultimately chose to become naturalized citizens.16 Compared to o

50、ther international STEM PhD graduates,Chinese nationals are much less likely to leave the United States after earning their degrees.Center for Security and Emerging Technology|10 Figure 4.Immigration Status of Chinese STEM PhD Graduates as of February 2017,by Graduation Year Source:2017 NSF Survey o

51、f Doctorate Recipients(see Appendix D for detailed data).In recent years,some U.S.policymakers have pushed to restrict the number of visas awarded to Chinese STEM students,arguing that too many return to China and work on projects that undermine U.S.economic and national security.However,our finding

52、s suggest these fears of a“reverse brain drain”are largely unfounded,at least among STEM PhD graduates.17 If anything,available data supports the Chinese Communist Partys concern that China is losing STEM talent to the United States and other countries.18 India Nearly 28,000 Indian nationals earned

53、STEM PhDs from U.S.universities between 2000 and 2015,accounting for roughly 16 percent of all international graduates during Center for Security and Emerging Technology|11 that period.Like their Chinese counterparts,a large majority of Indian graduates(87 percent)stay in the United States after gra

54、duation.However,their journey through the immigration system tended to take more time than for other international graduates.Figure 5 shows the immigration status of Indian STEM PhDs who graduated between 2000 and 2017.19 Indian nationals have followed the same general trajectory as other internatio

55、nal students,living as temporary residents immediately after graduation,and later obtaining permanent residency and eventually citizenship.Figure 5.Immigration Status of Indian STEM PhD Graduates as of February 2017,by Graduation Year Source:2017 NSF Survey of Doctorate Recipients(see Appendix E for

56、 detailed data).However,the share of graduates who maintain long-term temporary visas is higher among Indian nationals than those from other countries.In February 2017,about 12 percent of Indian STEM PhD graduates who earned their doctorates between 2004 and 2007 were living as temporary residents,c

57、ompared to just 5 percent of Chinese nationals and 6 percent of international graduates overall.This trend is largely a product of the country caps for green cards,as discussed above.Center for Security and Emerging Technology|12 In recent years,demand for green cards among Indian nationals has far

58、exceeded the supply,creating an extensive backlog.20 As of April 2021,more than 380,000 Indian nationals were still awaiting employment-based green cards after having their applications approved.21 This trend is relatively recenteveryone in the current backlog applied for permanent residency in 2010

59、 or later22which explains why the delay is not reflected in Figure 5.If this backlog persists,it is reasonable to expect that a larger percentage of recent Indian PhD graduates will maintain long-term temporary residency or leave the United States altogether.23 Conclusion U.S.universities remain a t

60、op destination for students around the world,particularly at the graduate level.International students accounted for more than 40 percent of the roughly half million STEM PhDs awarded by U.S.universities between 2000 and 2019.24 Those who stay in the country after receiving their degrees strengthen

61、the domestic STEM workforce and make valuable contributions to the economy and society.We found more than 77 percent of the roughly 178,000 international students who obtained STEM PhDs from U.S.universities between 2000 and 2015 were still living in the country as of February 2017.Stay rates remain

62、 high even among older graduatesat least 65 percent of every years graduating class since 2000 remains in the United States,and since 2008,no graduating class has had a stay rate below 73 percent.Furthermore,we found graduates who specialized in STEM were far more likely to stay in the United States

63、 than those who studied non-STEM fields,though stay rates across STEM disciplines were generally consistent.Additionally,we found stay rates vary significantly by nationality.Chinese and Indian nationalswho collectively account for almost half of the international STEM PhD populationremained at much

64、 higher rates than graduates from other countries.PhD graduates who remain in the United States generally follow a similar path through the immigration system,with the majority first living as temporary residents,then obtaining permanent residency,and then becoming naturalized citizens.However,due t

65、o country caps on green cards,Indian nationals face longer wait times than applicants from other countries.If the current backlog of permanent residency applicants persists,it is reasonable to expect that a greater share of Indian nationals will rely on long-term temporary visas or leave the United

66、States altogether.Center for Security and Emerging Technology|13 Authors Jack Corrigan is a research analyst at CSET,where James Dunham is a data scientist.Remco Zwetsloot is a trustee fellow in the International Security Program at the Center for Security and International Studies,and was formerly

67、a research fellow at CSET.Acknowledgements The authors would like to thank Catherine Aiken,David Bier,Amy Burke,Wan-Ying Chang,Jacob Feldgoise,Shelton Fitch,Rita Konaev,Igor Mikolic-Torreira,Leigh Ann Pennington,and Darius Singpurwalla for their valuable feedback,reviews,and editorial support.2022 b

68、y the Center for Security and Emerging Technology.This work is licensed under a Creative Commons Attribution-Non Commercial 4.0 International License.To view a copy of this license,visit https:/creativecommons.org/licenses/by-nc/4.0/.Document Identifier:doi:10.51593/20210023 Center for Security and

69、Emerging Technology|14 Appendices Appendix A.Data Table for Figure 1 Table A1.Stay Rates of International STEM PhD Graduates,20002015 Graduation Year N(Stayed)N(Left)Stay Rate 2015*5,324 1,050 84%2014 12,143 2,024 86%2013 11,252 3,227 78%2012 10,791 3,068 78%2011 10,161 3,038 77%2010 8,844 3,310 73%

70、2009 9,539 3,051 76%2008 9,531 2,408 80%2007 9,883 3,653 73%2006 9,031 2,939 75%2005 10,033 2,710 79%2004 6,058 2,267 73%2003 5,076 2,752 65%2002 6,179 2,291 73%2001 6,109 2,195 74%2000 6,575 1,799 79%Source:2017 NSF Survey of Doctorate Recipients.*The most recent graduation cohort appears to be sma

71、ller due to lags in data collection.Center for Security and Emerging Technology|15 Appendix B.Stay Rates by Country Table B1.Stay Rates of International STEM PhD Graduates by Nationality,20002015 All International All International(excl.China/India)China India Year N(total)Stay Rate N(total)Stay Rat

72、e N(total)Stay Rate N(total)Stay Rate 20142015 20,541 85%10,336 76%6,813 94%3,392 94%20122013 28,338 78%15,670 71%7,637 86%5,031 86%20102011 25,353 75%12,940 65%7,413 85%5,000 86%20082009 24,529 78%13,236 70%7,401 89%3,892 84%20062007 25,506 74%12,246 60%8,449 90%4,811 82%20042005 21,068 76%11,279 6

73、1%7,175 94%2,614 92%20022003 16,298 69%9,550 54%5,256 91%1,492 86%20002001 16,678 76%9,974 64%5,296 96%1,408 88%Source:2017 NSF Survey of Doctorate Recipients.Appendix C.Stay Rates and Immigration Statuses of International STEM PhD Graduates Table C1.Immigration Statuses of International STEM PhD Gr

74、aduates as of February 2017 Left United States Naturalized Citizens Permanent Residents Temporary Residents Graduation Cohort N%Total N%Total N%Total N%Total 20122015 9,369 19%2,476 5%15,499 32%21,536 44%20082011 11,807 24%7,868 16%22,856 46%7,351 15%20042007 11,569 25%14,108 30%18,202 39%2,696 6%20

75、002003 9,037 27%15,853 48%7,428 23%659 2%Source:2017 NSF Survey of Doctorate Recipients.Center for Security and Emerging Technology|16 Appendix D.Immigration Statuses of Chinese Nationals Table D1.Immigration Statuses of Chinese STEM PhD Graduates as of February 2017 Left United States Naturalized C

76、itizens Permanent Residents Temporary Residents Graduation Cohort N%Total N%Total N%Total N%Total 20142015 394 6%246 4%1,247 18%4,926 72%20122013 1,083 14%259 3%3,150 41%3,140 41%20102011 1,079 15%616 8%4,115 56%1,602 22%20082009 835 11%1,332 18%4,551 62%650 9%20062007 859 10%1,944 23%5,089 60%551 7

77、%20042005 412 6%3,138 44%3,461 48%164 2%20022003 475 9%3,076 59%1,587 30%118 2%20002001 193 4%3,678 69%1,424 27%1 0%Source:2017 NSF Survey of Doctorate Recipients.Appendix E.Immigration Statuses of Indian Nationals Table E1.Immigration Statuses of Indian STEM PhD Graduates as of February 2017 Left U

78、nited States Naturalized Citizens Permanent Residents Temporary Residents Graduation Cohort N%Total N%Total N%Total N%Total 20142015 211 6%168 5%432 13%2,536 76%20122013 717 14%298 6%1,657 33%2,359 47%20102011 700 14%454 9%2,450 49%1,376 28%20082009 638 16%746 19%1,827 47%676 17%20062007 872 18%1,03

79、5 22%2,192 46%712 15%20042005 204 8%1,250 48%953 36%207 8%20022003 202 14%649 43%545 37%96 6%20002001 172 12%961 68%251 18%24 2%Source:2017 NSF Survey of Doctorate Recipients.Center for Security and Emerging Technology|17 Endnotes 1“Survey of Doctorate Recipients:2017-Technical Notes,”National Scien

80、ce Foundation,accessed January 2022,https:/ncsesdata.nsf.gov/doctoratework/2017/sdr_2017_tech_notes.pdf#page=2.The sample of 124,580 individuals represents roughly 11 percent of the total population(1,103,200 individuals).2 Catherine Aiken,James Dunham,and Remco Zwetsloot,“Immigration Pathways and P

81、lans of AI Talent”(Center for Security and Emerging Technology,September 2020),https:/cset.georgetown.edu/publication/immigration-pathways-and-plans-of-ai-talent/.3 Remco Zwetsloot,Jack Corrigan,Emily Weinstein,Dahlia Peterson,Diana Gehlhaus,and Ryan Fedasiuk,“China is Fast Outpacing U.S.STEM PhD Gr

82、owth”(Center for Security and Emerging Technology,August 2021),https:/cset.georgetown.edu/publication/china-is-fast-outpacing-u-s-stem-phd-growth/.4 Tina Huang,Zachary Arnold,and Remco Zwetsloot,“Most of Americas Most Promising AI Startups Have Immigrant Founders”(Center for Security and Emerging Te

83、chnology,October 2020),https:/cset.georgetown.edu/publication/most-of-americas-most-promising-ai-startups-have-immigrant-founders/.5 We include five academic fields in our definition of STEM:biological,agricultural,and environmental life sciences;computer and information science;engineering;mathemat

84、ics and statistics;and physical sciences,geosciences,and ocean sciences.Our analysis excludes PhD graduates with degrees in social sciences.6 Remco Zwetsloot,James Durham,Zachary Arnold,and Tina Huang,“Keeping Top AI Talent in the United States”(Center for Security and Emerging Technology,December 2

85、019),https:/cset.georgetown.edu/wp-content/uploads/Keeping-Top-AI-Talent-in-the-United-States.pdf#page=23;Aiken,Dunham,and Zwetsloot,“Immigration Pathways and Plans of AI Talent”;Catherine Aiken,James Dunham,and Remco Zwetsloot,“Career Preferences of AI Talent”(Center for Security and Emerging Techn

86、ology,June 2020),https:/cset.georgetown.edu/publication/career-preferences-of-ai-talent/.7 Zwetsloot et al.,“Keeping Top AI Talent in the United States.”8 H-1B visa holders with pending green card applications may continue renewing their visas in one-year increments after the initial three-year exte

87、nsion.Center for Security and Emerging Technology|18 9 Zachary Arnold,Roxanne Heston,Remco Zwetsloot,and Tina Huang,“Immigration Policy and the U.S.AI Sector”(Center for Security and Emerging Technology,September 2019),https:/cset.georgetown.edu/publication/immigration-policy-and-the-u-s-ai-sector/;

88、and Zwetsloot et al.,“Keeping Top AI Talent in the United States.”10 There are multiple categories under which people can apply for permanent residency,including EB-1(for those with“extraordinary ability”or“outstanding professors and researchers”),EB-2(for those with“exceptional ability,”most common

89、ly used by those with graduate degrees),and EB-3(college graduates).Graduate students typically apply under the EB-2 category,though generally they are also eligible for EB-3 visas.11 Due to privacy considerations,NSF was only able to provide data on four-year cohorts.12 Julia Gelatt,“Explainer:How

90、the U.S.Legal Immigration System Works”(Migration Policy Institute,April 2019),https:/www.migrationpolicy.org/content/explainer-how-us-legal-immigration-system-works.13 David J.Bier,“Employment-Based Green Card Backlog Hits 1.2 Million in 2020,”Cato at Liberty,November 20,2020,https:/www.cato.org/bl

91、og/employment-based-green-card-backlog-hits-12-million-2020.14 Kimberly Bennett,“Bill Passed by House Benefits Immigrants in STEM Fields,Entrepreneurs in Start-Ups,”JDSupra,February 9,2022,https:/ COMPETES Act of 2022,H.R.4521,117th Congress(2021),https:/docs.house.gov/billsthisweek/20220131/BILLS-1

92、17HR4521RH-RCP117-31.pdf.15 Remco Zwetsloot,Jacob Feldgoise,and James Durham,“Trends in U.S.Intention-to-Stay Rates of International PhD Graduates Across Nationality and STEM Fields”(Center for Security and Emerging Technology,April 2020),https:/cset.georgetown.edu/publication/trends-in-u-s-intentio

93、n-to-stay-rates-of-international-ph-d-graduates-across-nationality-and-stem-fields/.16 Chinese law does not permit dual citizenship,so Chinese nationals automatically lose their citizenship after completing the naturalization process in the United States.See:Embassy of the Peoples Republic of China

94、in the United States of America,“Nationality Law of the Peoples Republic of China,”accessed October 2021,http:/www.china-embassy.org/eng/ywzn/lsyw/vpna/faq/t710012.htm.17 While our analysis shows stay rates among international STEM PhD graduates remain consistently high,we were unable to assess the

95、United States ability to attract and retain foreign nationals at the bachelors and masters level,as neither the NSF nor any organization Center for Security and Emerging Technology|19 we know of collects such data.Additional research into the post-graduation stay rates of international bachelors and

96、 masters students would give us a more comprehensive understanding of the STEM talent pipeline in the United States.18 Remco Zwetsloot,“Sen.Tom Cotton suggested Chinese STEM students head home after studying in the U.S.The research shows otherwise,”The Washington Post,April 28,2020,https:/ Remco Zwe

97、tsloot,“US-China STEM Talent Decoupling:Background,Policy,and Impact”(Johns Hopkins Applied Physics Laboratory,2020),https:/www.jhuapl.edu/assessing-us-china-technology-connections/dist/6f836fc5733036e578c346897c5f623a.pdf.19 Due to privacy considerations,NSF restricted data on the size of certain c

98、ohorts of Chinese and Indian nationals who graduated between 20002005 and held temporary residency in February 2017.We estimated these figures indirectly using other public SDR data.20 David J.Bier,“Backlog for Skilled Immigrants Tops 1 Million:Over 200,000 Indians Could Die of Old Age While Awaitin

99、g Green Cards”(Cato Institute,March 30,2020),https:/www.cato.org/publications/immigration-research-policy-brief/backlog-skilled-immigrants-tops-1-million-over#projection-future-wait-times.21 U.S.Customs and Immigration Services,“Form I-140,I-360,I-526 Approved Employment-Based Petitions Awaiting Vis

100、a Availability by Preference and Country of Birth,”U.S.Department of Homeland Security,April 2021,https:/www.uscis.gov/sites/default/files/document/reports/EB_I140_I360_I526_performancedata_fy2021_Q1_Q2.pdf.22 U.S.Department of State,“Visa Bulletin for April 2021,”March 5,2021,https:/travel.state.go

101、v/content/travel/en/legal/visa-law0/visa-bulletin/2021/visa-bulletin-for-april-2021.html.23 The United States is already seeing large numbers of Indian nationals,including those educated in the country,flock to other countries with less restrictive immigration systems,such as Canada.For more informa

102、tion,see:Zachary Arnold,“Canadas Skilled Immigration System Increasingly Draws Talent from the United States”(Center for Security and Emerging Technology,July 2020),https:/cset.georgetown.edu/publication/canadas-immigration-system-increasingly-draws-talent-from-the-united-states/.24 Zwetsloot et al.,“China is Fast Outpacing U.S.STEM PhD Growth.”