Table 4.

Model selection tests for citation distributions, Scopus, 1998–2002, 5-year citation window

Scopus subject area of science	p value	Exponential		Weibull		Log-normal		Tsallis		Yule		Digamma		PL with cut-off
		LR	p	LR	p	LR	p	LR	p	LR	p	LR	p	NLR	p
Agricultural and Biological Sciences	0.566	20.740	0.009	0.338	0.779	−0.096	0.782	0.054	0.890	−0.011	0.858	1.048	0.295	−0.268	0.464
Arts and Humanities	0.005	6.287	0.457	−6.93	0.023	−6.56	0.025	−4.325	0.189	−1.38	0.000	−1.991	0.046	−7.37	0.000
Biochemistry, Genetics and Mol. Biol.	0.175	204.5	0.000	1.22	0.758	−1.12	0.473	−1.227	0.479	−0.155	0.108	1.553	0.121	−0.567	0.287
Business, Management and Accounting	0.000	34.390	0.034	−9.60	0.013	−9.24	0.013	−7.279	0.065	−1.39	0.000	−2.072	0.038	−9.98	0.000
Chemical Engineering	0.099	69.480	0.001	−0.021	0.994	−0.972	0.480	0.025	0.990	−0.358	0.187	0.710	0.477	−0.78	0.211
Chemistry	0.110	736.0	0.000	7.48	0.262	−2.67	0.204	1.290	0.687	−0.999	0.060	3.956	0.000	−3.31	0.010
Computer Science	0.000	609.4	0.000	−7.05	0.248	−8.80	0.035	−6.719	0.132	−2.00	0.000	0.664	0.507	−5.23	0.001
Decision Sciences	0.000	77.730	0.001	−6.71	0.046	−6.81	0.048	−.0275	0.956	−2.66	0.000	−1.176	0.240	−5.91	0.001
Earth and Planetary Sciences	0.000	459.7	0.000	−4.69	0.451	−7.52	0.045	−4.928	0.264	−1.95	0.000	1.164	0.244	−5.69	0.001
Economics, Econometrics and Finance	0.000	45.080	0.021	−21.6	0.000	−20.4	0.000	−17.027	0.002	−2.68	0.000	−3.408	0.001	−22.9	0.000
Energy	0.825	20.630	0.065	0.357	0.789	−0.072	0.838	0.347	0.690	−0.023	0.884	0.813	0.416	−0.119	0.625
Engineering	0.000	825.5	0.000	–	–	−7.98	0.032	−0.763	0.877	−2.71	0.000	2.498	0.013	−7.52	0.000
Environmental Science	0.506	26.730	0.104	0.003	0.999	−0.422	0.685	−0.333	0.793	−0.114	0.334	0.303	0.762	−0.18	0.547
Immunology and Microbiology	0.049	170.3	0.000	−1.85	0.539	−2.48	0.176	−1.111	0.496	−0.268	0.076	1.643	0.100	−3.98	0.005
Materials Science	0.193	233.4	0.000	2.02	0.610	−1.02	0.460	−0.034	0.987	−0.412	0.178	1.852	0.064	−0.850	0.192
Mathematics	0.012	414.8	0.000	−1.54	0.784	−4.97	0.083	−0.264	0.943	−1.56	0.007	1.694	0.090	−5.19	0.001
Medicine	0.000	2740.0	0.000	–	–	−7.78	0.043	−4.566	0.309	−2.03	0.000	6.142	0.000	−5.62	0.001
Neuroscience	0.896	11.920	0.072	−0.018	0.987	−0.178	0.726	−0.066	0.888	−0.020	0.637	0.549	0.583	−0.285	0.451
Nursing	0.256	21.520	0.012	−0.284	0.803	−0.372	0.580	−0.048	0.936	−0.045	0.565	0.716	0.474	−0.733	0.226
Pharmacology, Toxicology and Pharm.	0.865	47.520	0.000	−0.361	0.844	−0.747	0.449	−0.002	0.999	−0.148	0.337	1.016	0.309	−1.24	0.115
Physics and Astronomy	0.797	706.2	0.000	19.5	0.006	0.048	0.646	0.954	0.495	0.091	0.771	4.514	0.000	0.000	1.000
Psychology	0.812	53.220	0.000	0.186	0.920	−0.460	0.562	0.129	0.904	−0.112	0.475	1.201	0.230	−0.791	0.208
Social Sciences	0.007	173.3	0.000	−3.56	0.366	−4.27	0.114	0.0774	0.983	−1.43	0.007	0.692	0.489	−4.21	0.004
Veterinary	0.017	38.090	0.000	0.841	0.598	−0.183	0.677	1.953	0.330	−0.047	0.874	1.520	0.128	−0.542	0.298
Dentistry	0.011	11.830	0.200	−6.60	0.025	−6.26	0.028	−3.714	0.257	−1.28	0.000	−1.958	0.050	−7.14	0.000
Health Professions	0.352	38.620	0.001	−0.944	0.599	−1.10	0.352	−0.395	0.760	−0.192	0.189	0.569	0.569	−1.63	0.071
Multidisciplinary	0.100	98.560	0.001	−1.37	0.595	−1.67	0.339	−1.497	0.377	−0.067	0.069	0.549	0.583	−1.44	0.090
All Sciences	0.076	672.3	0.000	18.30	0.009	−0.125	0.797	−0.007	0.992	−0.054	0.625	4.578	0.000	−0.240	0.488

Second column gives the p value for the hypothesis that the data follow a power-law model. “–” means that the maximum likelihood estimator did not converge. Positive values of the log-likelihood ratio (LR) or the normalized log-likelihood ratio (NLR) indicate that the power-law model is favored over the alternative