B · Which trades
Field concentration
0.104Median from 1750
Key point
From 1750 the decade field concentration stays between 0.089 and 0.117; an even split across 17 fields gives 0.059.
- Definition
- Herfindahl index of field shares among classified grants in each decade, 'other' excluded.
- Formula
- HHI = Σ (field share)²
- How to read it
- Higher means grants concentrate in fewer fields. With 17 fields an even spread gives 1/17 ≈ 0.059.
- Caveats
- The early decades have few grants, so the index swings widely. The index inherits the field classification's precision of about two in three.
Table
| Decade | Total | Classified | HHI | Largest field | Largest field's share | 'Other' share |
|---|---|---|---|---|---|---|
| 1610 | 15 | 14 | 0.133 | water | 21.4% | 6.7% |
| 1620 | 33 | 25 | 0.117 | metals | 20.0% | 24.2% |
| 1630 | 75 | 61 | 0.100 | mining | 16.4% | 18.7% |
| 1640 | 4 | 4 | 0.375 | metals | 50.0% | 0.0% |
| 1660 | 31 | 28 | 0.105 | mining | 14.3% | 9.7% |
| 1670 | 50 | 46 | 0.104 | metals | 15.2% | 8.0% |
| 1680 | 53 | 48 | 0.119 | textiles | 20.8% | 9.4% |
| 1690 | 102 | 88 | 0.098 | transport | 14.8% | 13.7% |
| 1700 | 22 | 20 | 0.180 | glass_ceramics | 25.0% | 9.1% |
| 1710 | 38 | 35 | 0.096 | textiles | 17.1% | 7.9% |
| 1720 | 89 | 79 | 0.098 | transport | 15.2% | 11.2% |
| 1730 | 56 | 49 | 0.158 | transport | 30.6% | 12.5% |
| 1740 | 82 | 78 | 0.110 | textiles | 19.2% | 4.9% |
| 1750 | 92 | 86 | 0.107 | medicine | 16.3% | 6.5% |
| 1760 | 205 | 177 | 0.104 | transport | 18.1% | 13.7% |
| 1770 | 294 | 264 | 0.103 | textiles | 20.5% | 10.2% |
| 1780 | 477 | 412 | 0.093 | textiles | 16.3% | 13.6% |
| 1790 | 646 | 552 | 0.094 | textiles | 20.1% | 14.6% |
| 1800 | 920 | 779 | 0.097 | textiles | 18.7% | 15.3% |
| 1810 | 1,134 | 927 | 0.089 | transport | 15.6% | 18.3% |
| 1820 | 1,448 | 1,176 | 0.117 | textiles | 20.8% | 18.8% |
| 1830 | 2,435 | 2,011 | 0.111 | textiles | 21.3% | 17.4% |
| 1840 | 4,552 | 3,519 | 0.104 | textiles | 18.8% | 22.7% |
| 1850 | 1,434 | 1,152 | 0.108 | textiles | 21.7% | 19.7% |
sampledReliability card
Rule-based classification: assigned by word rules; below, the precision measured on an independently coded sample
- Text recoding, field (stratified sample)
- 145/212 (68%, 95% CI 62–74%)
- Cohen's kappa
- 0.67
- Precision weighted by field shares
- 67%
- Agreement by field
- agriculture 10/11; arms 5/11; building 6/11; chemicals 10/11; food_drink 6/11; fuel_light 9/11; glass_ceramics 9/11; instruments 9/11; medicine 7/11; metals 10/11; mills 10/11; mining 7/11; other 5/25; printing_paper 8/11; steam_power 8/11; textiles 11/11; transport 6/11; water 9/11
Sources
- Bennet Woodcroft, Titles of Patents of Invention, Chronologically Arranged, from March 2, 1617 (14 James I.) to October 1, 1852 (16 Victoriae), London: Eyre & Spottiswoode, 1854, 2 parts (Nos. 1–14,359). Entries were split from the word coordinates of the Internet Archive OCR of the University of Illinois copy (
chronologicalin1617grea_0,chronologicalind1617grea); 115 pages on which that OCR lost entry numbers were read again from the page images with tesseract 5. (public domain, 1854; https://archive.org/details/chronologicalin1617grea_0)