Innovation Policy and the Economy, Volume 11

(column 2). The data and results are described in detail in Jones (2010). The third group
consists of more ‘ordinary’ inventors and considers the age at first patent, using U.S. patent data
since 1975 across all technological fields. These individuals show a substantial increase in mean
age at first patent, at an equivalent rate of 6.57 years per century (column 3). These data and
methods are described in detail in Jones (2009).

The similarity in these age trends, and the fact that they prevail both among great
scientists, among great technological inventors, and among more ordinary inventors, point to a
general aging phenomenon. As shown in columns 4-6 of Table 1, these raw age trends also
persist - and strengthen to 7 or 8 years per century - when controlling for field, country of birth,
or the institutional environment of the research. Age trends are also increasing quite generally
when examine individual subfields separately,⁴ either for great invention or patenting (see Jones
2009 and Jones and Weinberg 2010).

The rise in the mean age of great achievement over the 20^th century is dramatic and may
represent shifts in research productivity at various phases in the life-cycle. Jones (2010)
therefore further analyzes the trends in age at great achievement, locating any shifts in life-cycle
research productivity while also accounting for shifts in the underlying population age
distribution.⁵ As shown in Figure 2A, the analysis shows underlying shifts in life-cycle
productivity, beyond any population aging effect. In particular, there is a large decline in the
propensity of Nobel Prize winners and great technological inventors to produce great
achievements in their 20s and early 30s. Peak productivity has increased by about 8 years, with
the effect coming entirely from a collapse in productivity at young ages.

⁴ Albeit with some interesting and informative dynamics, as will be discussed below.

⁵ The aging trends among Nobel Prize winners and great technological inventors may follow in part from aging of
the underlying population distribution. In particular, if there are more scientists alive and active at older ages, then it
is increasingly likely that great ideas will come from an older scholar. Jones (2010) shows that about the half of the
age trend in Table 1 columns 1 and 2 is driven by the aging population of scholars, while the remaining half is
driven by declining research productivity early in the life-cycle. See Jones (2010).

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