CD Index & Scientific Disruptiveness Simulator

Exploring the Metascience Debate: CD Index Math, Field Expansion & Citation Artifacts
Focal Paper (F)
Cited Predecessor (B)
Disruption Cites ($N_i$: Cites F, skips B)
Consolidation Cites ($N_j$: Cites F & B)
Predecessor Cites ($N_k$: Cites B, skips F)
CD Index ($CD_5$) +0.60
Disruptive ($N_i$) 6
Consolidating ($N_j$) 1
B-Only ($N_k$) 3
Classification Highly Disruptive
Metascience Insight: High CD Index ($CD_5 > 0$) means subsequent work references the focal discovery without needing its predecessors, signaling a paradigm shift.

Presets & Debates

Citations Network Controls

Simulates field growth & longer reference lists since 1950

Unpacking the Science Disruptiveness Debate

In 2023, a widely cited study in Nature analyzed tens of millions of papers and patents from 1945 to 2010 using the Consolidation-Disruption (CD) Index, concluding that scientific progress had become dramatically less "disruptive" over time. However, recent metascience research reported in The Economist highlights a fundamental flaw in using CD Index trends over decades: changing citation norms.

CD Index Equation:
$$CD = \frac{N_i - N_j}{N_i + N_j + N_k}$$
Where:
- $N_i$: Papers citing ONLY Focal Paper $F$ (replaces predecessor)
- $N_j$: Papers citing BOTH Focal Paper $F$ and Predecessor $B$ (builds upon)
- $N_k$: Papers citing ONLY Predecessor $B$ (ignores focal paper)
- Range: -1.0 (Pure Consolidation) to +1.0 (Pure Disruption)

The Metascience Twist: Citation Inflation

As fields expand and authors include significantly longer bibliographies (increasing average references per paper from 10 to 50+ over 70 years), the probability that a paper cites both $F$ and $B$ mechanically skyrockets ($N_j$ grows faster than $N_i$). Use the Reference List Expansion Factor slider above to observe how expanding citation behavior pushes the CD Index toward negative values even if underlying scientific disruption remains unchanged!

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