DO PATENT POOLS ENCOURAGE INNOVATION? EVIDENCE ...

4
FIGURE 3 – AVERAGE PATENTS BY SUBCLASS AND YEAR
Pool Start Year
3.5
3
Average Patents Per Year
2.5
2
1.5
1
0.5
-9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10
Pool Subclass Cross-ref Subclass Other Subclass
Notes: Data include 45,917 subclasses in 103 main classes that include at least pool patent. The timing of
invention is measured by the year of the patent application; t=0 denotes the year when the pool formed.
Pool subclasses are listed as the primary subclass by at least one pool patent; pool patents are patents that
were included in the initial pool agreement. Cross-reference subclasses are listed as the secondary, crossreference
subclass for at least one pool patent and not listed as a primary subclass.
7
FIGURE 4 – AVERAGE PATENTS BY SUBCLASS AND YEAR FOR POOL
SUBCLASSES WITH DIFFERENT NUMBERS OF POOL PATENTS
Pool Start Year
6
5
4
3
2
1
0
-9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10
1 Patent 2 Patents 3+ Patents
Notes: To measure pooling at the level of subclasses, this figure distinguishes pool subclasses with 1, 2,
and 3 pool patents. Data include 45,917 subclasses in 103 main classes that include at least pool patent.
The timing of invention is measured by the year of the patent application; t=0 denotes the year when the
pool formed. Pool subclasses are listed as the primary subclass on at least one patent that was included in
the initial agreement of a pool.
2