patent {flexmix}R Documentation

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")

Format

A data frame with 70 observations on the following 4 variables.

Company

Name of company.

Patents

Number of patents.

RDS

R\&D spending per sales.

lgRD

Logarithmized R\&D spendings (in millions of dollars).

Details

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

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.

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"),
                      concomitant=FLXPmultinom(~RDS),
                      nrep=5, data=patent)
plot(Patents ~ lgRD, data=patent,
     pch=as.character(clusters(patentMix)))
ordering <- order(patent$lgRD)
apply(fitted(patentMix), 2, function(y)
      lines(sort(patent$lgRD), y[ordering]))

[Package flexmix version 2.3-6 Index]