flexmix (version 2.0-1)

patent: Patents and R&D spending

Description

Number of patents, R&D spending and sales in millions of dollar for 70 pharmaceutical and biomedical companies in 1976.

Usage

data("patent")

source

P. Wang, I.M. Cockburn and M.L. Puterman (1998): Analysis of Patent Data - A Mixed-Poisson-Regression-Model Approach. Journal of Business & Economic Statistics 16 (1), pages 27-41.

Details

The data is taken from the National Bureau of Economic Research R&D Masterfile.

References

B.H. Hall, C. Cummins, E. Laderman and J. Mundy (1988): The R&D Master File Documentation. Technical Working Paper 72, National Bureau of Economic Research. Cambridge, MA.

Examples

data("patent")
patentMix <- stepFlexmix(Patents ~ lgRD, k=3,
                      model=FLXMRglm(family="poisson"),
                      nrep=5, data=patent)
plot(Patents ~ lgRD, data=patent,
     pch=as.character(cluster(patentMix)))
ordering <- order(patent$lgRD)
apply(fitted(patentMix), 2, function(y)
      lines(sort(patent$lgRD), y[ordering]))