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 2.2-4 Index]