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Bulgaria vs Romania

On research quality in 2022-now, Romania ranks #41 in the world and Bulgaria #77, of 189 countries. Bulgaria stands higher in 2 of the 25 fields both publish in, Romania in 23.

Research profiles alike: 0.62similar shapes of research, whatever their size. How it is measured

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Bulgaria

World rank, 2022-now
#77
#78 all time
Works, 2022-now
36k
fractional
Top-10% rate
4.8%
share of its work among the world's most cited
Open access
44%
of its works free to read

Strongest relative focus: General Energy, Tourism, Leisure and Hospitality Management, Numerical Analysis.

Romania

World rank, 2022-now
#41
#61 all time
Works, 2022-now
85k
fractional
Top-10% rate
9.1%
share of its work among the world's most cited
Open access
58%
of its works free to read

Strongest relative focus: General Energy, Orthodontics, Music.

Who leads, measure by measure?

Romania leads on 5 of 9 measures: research quality, excellence for its fields, output, top-10% rate and open access. Bulgaria leads on 3 of 9 measures: citations per work, international co-authorship and growth. The two are level on institutions in the world top 100.

Bulgaria 31 level5 Romania
  1. #77Research qualityworld rank of 189 countries, 2022-now#41
  2. 0.52×Excellence for its fieldsits top-10% rate against what its topics predict; 1.00× is as expected1.10×
  3. 36kOutputfractional works, 2022-now85k
  4. 4.8%Top-10% rateshare of its works among the world's most cited9.1%
  5. 9.6Citations per workall time, per fractional work7.8
  6. 0World top 100institutions it holds among the world's best 1000
  7. 44%Open accessof its works free to read, all time58%
  8. 24%Internationalof its works written with co-authors abroad, all time17%
  9. +22%Growthworks in 2022-25 against 2018-21; half a bar is no change+9%

A rank is drawn as its standing: the longer the bar, the nearer the top. Anything else is drawn against the larger of the two, and two values a hair apart are called level. Quality, excellence and the top-10% rate are explained in the methodology.

Who leads in each field?

Bulgaria stands higher in 2 of 25 fields, Romania in 23. Romania leads most in Earth and Planetary Sciences (#39 against #70); Bulgaria leads most in Neuroscience (#41 against #46). Each bar is that side's standing among all countries ranked in the field: the full bar is first place.

Bulgaria 223 Romania
  1. #79Agricultural and Biological Sciences#53
  2. #57Arts and Humanities#49
  3. #60Biochemistry, Genetics and Molecular Biology#48
  4. #81Business, Management and Accounting#55
  5. -Chemical Engineering#37
  6. #50Chemistry#51
  7. #83Computer Science#55
  8. #68Decision Sciences#48
  9. #50Dentistry#33
  10. #70Earth and Planetary Sciences#39
  11. #75Economics, Econometrics and Finance#55
  12. #69Energy#51
  13. #83Engineering#53
  14. #87Environmental Science#43
  15. #94Health Professions#53
  16. #60Immunology and Microbiology#44
  17. #58Materials Science#47
  18. #54Mathematics#41
  19. #94Medicine#55
  20. #41Neuroscience#46
  21. -Nursing#46
  22. -Pharmacology, Toxicology and Pharmaceutics#34
  23. #57Physics and Astronomy#42
  24. #85Psychology#51
  25. #104Social Sciences#61

Standing is the percentile of world rank within each field, 2022-now; the printed number is the rank itself. A dash means the field is too small there to rank. How sides are compared.

The numbers behind each field

Click a heading to sort. The side that does better in a pair of columns is shaded: a lower rank, a higher rate, more works.

Field Bulgaria rankRomania rank Bulgaria top 10%Romania top 10% Bulgaria worksRomania works
Agricultural and Biological Sciences #79 #53 5.9% 11.6% 2.5k 3.8k
Arts and Humanities #57 #49 6.0% 6.7% 1k 4k
Biochemistry, Genetics and Molecular Biology #60 #48 5.2% 12.2% 1.6k 3k
Business, Management and Accounting #81 #55 5.4% 7.6% 1.2k 3.7k
Chemical Engineering - #37 - 5.1% - 263
Chemistry #50 #51 6.4% 8.7% 626 1k
Computer Science #83 #55 4.3% 7.2% 3.1k 6.1k
Decision Sciences #68 #48 4.3% 9.3% 412 1k
Dentistry #50 #33 4.4% 14.8% 410 1k
Earth and Planetary Sciences #70 #39 3.0% 8.3% 756 1.2k
Economics, Econometrics and Finance #75 #55 6.1% 8.7% 926 3k
Energy #69 #51 2.7% 6.5% 424 862
Engineering #83 #53 3.4% 5.8% 6.2k 13k
Environmental Science #87 #43 4.1% 8.9% 1.9k 4.1k
Health Professions #94 #53 3.7% 11.9% 674 1.7k
Immunology and Microbiology #60 #44 4.5% 13.1% 335 608
Materials Science #58 #47 3.7% 7.0% 1.1k 2.7k
Mathematics #54 #41 7.4% 10.7% 722 1.7k
Medicine #94 #55 4.8% 13.6% 5.9k 16k
Neuroscience #41 #46 5.2% 11.2% 435 961
Nursing - #46 - 16.8% - 398
Pharmacology, Toxicology and Pharmaceutics - #34 - 16.6% - 276
Physics and Astronomy #57 #42 4.0% 6.4% 817 1.4k
Psychology #85 #51 4.6% 9.0% 722 2.7k
Social Sciences #104 #61 6.5% 6.9% 3.3k 10k

What is each known for?

The keywords that describe each side's research, by fractional works in 2022-now and weighted toward what it does more of than the world.

Bulgaria

▲ more of its work than of the world's◆ about the world's share▼ less than the world's
All 40 words, with their numbers
  1. Climate Change1,519▲ 1.36×126 topics
  2. Machine Learning1,477◆ 1.08×97 topics
  3. Epidemiology1,397▼ 0.85×138 topics
  4. Sustainability1,336▲ 1.33×130 topics
  5. Sustainable Development1,218▲ 1.89×109 topics
  6. Renewable Energy1,186▲ 1.99×60 topics
  7. Deep Learning1,146▼ 0.81×85 topics
  8. Artificial Intelligence951▲ 1.62×65 topics
  9. Environmental Impact804◆ 1.15×74 topics
  10. Oxidative Stress777◆ 1.15×62 topics
  11. Energy Efficiency769▲ 2.0×46 topics
  12. Globalization741◆ 0.92×164 topics
  13. Big Data727▲ 1.85×35 topics
  14. Inflammation726▼ 0.83×83 topics
  15. Neural Networks716◆ 1.13×42 topics
  16. Educational Technology621▲ 1.28×46 topics
  17. Innovation595▲ 1.40×85 topics
  18. Remote Sensing569◆ 1.13×41 topics
  19. Economic Growth567▲ 1.69×36 topics
  20. Internet of Things566▲ 1.61×31 topics
  21. Biodiversity544▲ 1.74×38 topics
  22. Antioxidant505▲ 1.79×51 topics
  23. Supply Chain Management470▲ 1.27×27 topics
  24. E-Learning449◆ 1.13×25 topics
  25. Cyber-Physical Systems444▲ 4.1×9 topics
  26. Invasive Species444▲ 2.5×21 topics
  27. Security411▲ 1.50×31 topics
  28. Antioxidant Activity407▲ 1.59×32 topics
  29. Digital Transformation402▲ 1.81×32 topics
  30. Environmental Management393▲ 2.4×22 topics
  31. Smart Grid350▲ 2.4×10 topics
  32. Optimization331▲ 1.79×26 topics
  33. Biogeography319▲ 2.8×20 topics
  34. Power Electronics304▲ 2.3×8 topics
  35. Phylogeny238▲ 3.5×17 topics
  36. Taxonomy224▲ 3.8×15 topics
  37. Mediterranean219▲ 6.0×6 topics
  38. Black Sea165▲ 11×2 topics
  39. Caspian Sea160▲ 14×1 topic
  40. paleoceanography160▲ 14×1 topic

Romania

▲ more of its work than of the world's◆ about the world's share▼ less than the world's
All 40 words, with their numbers
  1. Epidemiology3,763◆ 1.00×140 topics
  2. Sustainability3,280▲ 1.41×137 topics
  3. Machine Learning2,912◆ 0.92×97 topics
  4. Climate Change2,713◆ 1.05×129 topics
  5. Deep Learning2,665▼ 0.81×85 topics
  6. Globalization2,600▲ 1.39×176 topics
  7. Renewable Energy2,190▲ 1.60×60 topics
  8. Inflammation2,092◆ 1.04×83 topics
  9. Sustainable Development2,054▲ 1.38×109 topics
  10. Environmental Impact1,995▲ 1.23×73 topics
  11. Artificial Intelligence1,769▲ 1.31×67 topics
  12. Education1,636◆ 1.00×155 topics
  13. Oxidative Stress1,524◆ 0.98×63 topics
  14. Economic Growth1,476▲ 1.91×36 topics
  15. Innovation1,410▲ 1.44×88 topics
  16. Quality of Life1,338◆ 0.98×61 topics
  17. Neural Networks1,301◆ 0.89×42 topics
  18. Biomedical Applications1,283◆ 1.14×36 topics
  19. Energy Efficiency1,242▲ 1.42×45 topics
  20. Human Rights1,237▲ 1.27×90 topics
  21. COVID-191,236◆ 1.00×34 topics
  22. Social Media1,232◆ 0.94×41 topics
  23. Identity1,231▲ 1.79×78 topics
  24. Cardiovascular Disease1,225◆ 1.13×39 topics
  25. Treatment1,201◆ 1.04×52 topics
  26. Supply Chain Management1,200▲ 1.41×27 topics
  27. Mental Health1,199◆ 0.88×48 topics
  28. Big Data1,164▲ 1.28×37 topics
  29. Internet of Things1,149▲ 1.41×33 topics
  30. Mechanical Properties1,136▲ 1.22×39 topics
  31. Risk Factors1,082◆ 1.04×37 topics
  32. Environmental Management962▲ 2.5×23 topics
  33. Literature910▲ 1.75×62 topics
  34. Security909▲ 1.43×31 topics
  35. Ethics892▲ 1.86×60 topics
  36. Tissue Engineering846▲ 1.47×13 topics
  37. European Union631▲ 3.0×29 topics
  38. International Relations591▲ 2.6×29 topics
  39. Regional Disparities397▲ 8.9×2 topics
  40. Social Perception355▲ 8.9×4 topics

Size is fractional works in the topics tagged with each word; colour is the word's share of the side's work against its share of the world's. Each word links to the topic it comes from most.

How has their output grown?

Romania has out-published Bulgaria every year since 2000, when it overtook it.

still counting10k20k30kRomania23k in 2025Bulgaria10k in 20251990200020102020

Fractional works per year.

Their share of all research

Growing output can still be a shrinking share, because all of science grows. Each line is a side as a percentage of every work published that year.

still counting0.20%0.40%0.60%Romania0.38% in 2025Bulgaria0.18% in 202519801990200020102020

Fractional works over all fractional works that year. How the balance of science has shifted.

How much of it reaches the world top 10%

The share of each side's works, year by year, that reached the world's 10% most cited for their field and year. The average of all institutions is 10.0% (why not 10%).

still counting5%10%15%Romania11.2% in 2025Bulgaria5.8% in 2025200020102020

A year with under 1% of the side's peak output is left out: a rate over a handful of papers says nothing. The latest years are still being cited.

Who holds more of the world's best institutions?

A country's average quality and the number of institutions it holds at the very top can disagree, and both are worth knowing. The counts are nested: an institution in the top 50 is also in the top 100.

Bulgaria 05 level0 Romania
  1. 0In the world top 500
  2. 0In the top 1000
  3. 0In the top 5000
  4. 0In the top 1,0000
  5. #51Elite capacityrank among 204 countries#51

Institutions ranked on research quality, 2022-now. Elite capacity counts a country's institutions by their worldwide rank, weighted so a place at #1 counts for more than one at #480.

Which publishes more research, Bulgaria or Romania?

Romania publishes 2.4× as much research as Bulgaria in 2022-now (85k against 36k fractional works).

Whose research has more impact, Bulgaria or Romania?

9.1% of Romania's research reaches the world's top 10% most cited, against 4.8% for Bulgaria.

Is Bulgaria or Romania growing faster?

Output in 2022-25 was +22% against 2018-21 for Bulgaria, and +9% for Romania.

Which has more open access research, Bulgaria or Romania?

58% of Romania's research is free to read, against 44% of Bulgaria's.

Which has more world-class institutions, Bulgaria or Romania?

Bulgaria holds 0 of the world's top 100 research institutions and Romania 0; in the top 1,000 it is 0 against 0.

Which institutions lead in each country?

The highest-ranked institutions on each side on research quality, 2022-now. The percentage is each institution's own top-10% rate: the share of its works that are among the world's 10% most cited for their field and year. Every figure stands alone, so they do not add up to 100%.

Bulgaria

  1. 1Bulgarian Academy of Sciences5.0% top 10% · 8.8k works
  2. 2College of Tourism8.7% top 10% · 779 works
  3. 3Angel Kanchev University of Ruse4.0% top 10% · 1.1k works
  4. 4Sofia University "St. Kliment Ohridski"5.3% top 10% · 2.3k works
  5. 5New Bulgarian University3.6% top 10% · 500 works
  6. 6South-West University "Neofit Rilski"4.9% top 10% · 486 works

Romania

  1. 1Ministry of Education19.4% top 10% · 712 works
  2. 2Bucharest University of Economic Studies8.5% top 10% · 3.5k works
  3. 3University of Oradea13.0% top 10% · 1.8k works
  4. 4West University of Timişoara9.2% top 10% · 1.9k works
  5. 5Ştefan cel Mare University of Suceava8.1% top 10% · 1.7k works
  6. 6Lucian Blaga University of Sibiu11.1% top 10% · 1.8k works

The number is the rank inside the country. The track on each row is the top-10% rate; the tick is the average of all institutions, 10.0% (how it is set): teal above it, red below. The ranking is the quality score, which compares the rate with what each institution's own topics predict and adds a small reward for size, so the rates do not fall in order.

Who are the top researchers on each side?

The most cited researchers on each side, among those ranked.

Bulgaria

  1. 1 A. Cimmino #8,111 worldwide 84k citations · 1,049 works
  2. 2 A. Cabrera #11,365 worldwide 33k citations · 472 works
  3. 3 L. Litov #17,576 worldwide 113k citations · 2,193 works
  4. 4 S. Stoykova #20,679 worldwide 47k citations · 461 works
  5. 5 V. Genchev #32,911 worldwide 54k citations · 539 works

Romania

  1. 1 D. Felea #4,035 worldwide 23k citations · 200 works
  2. 2 Ovidiu Chioncel #4,732 worldwide 55k citations · 351 works
  3. 3 Robert Ancuceanu #6,028 worldwide 74k citations · 151 works
  4. 4 Ionuţ Negoi #7,120 worldwide 154k citations · 380 works
  5. 5 Bogdan Oancea #7,278 worldwide 85k citations · 215 works