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Power-law citation distributions are not scale-free.
1The Racah Institute of Physics, The Hebrew University of Jerusalem, 9190401 Jerusalem, Israel.
Physical Review. E
|January 20, 2018
Summary
Scientific paper citation distributions appear as power laws but are nonstationary. Highly cited papers become "runaways," indicating citation dynamics are not scale-free, challenging traditional bibliometric models.
Area of Science:
- Bibliometrics
- Scientometrics
- Network Science
Background:
- Citation distributions of scientific papers often exhibit power-law characteristics.
- Understanding the temporal evolution of citation patterns is crucial for bibliometrics.
- Previous models often assume stationary citation dynamics.
Purpose of the Study:
- To analyze the time evolution of citation distributions for papers published in the same year.
- To investigate the nonstationarity of citation distributions and its underlying causes.
- To compare empirical findings with a new model of citation dynamics.
Main Methods:
- Statistical analysis of citation data over time.
- Measurement of citation trajectories for individual papers.
- Comparison of empirical data with a copying-redirection-triadic closure model.
Main Results:
- Citation distributions are nonstationary, with the power-law exponent decreasing over time.
- Low-cited papers' citation careers saturate within 10-15 years.
- Highly cited papers become 'runaways,' with citations increasing indefinitely, indicating a hidden dynamic scale.
Conclusions:
- Citation distributions, while appearing as power laws, are not scale-free due to runaway papers.
- The nonstationarity is driven by differential paper longevity and the emergence of highly cited 'runaways'.
- A model based on copying, redirection, and triadic closure explains these empirical observations.
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