Wooldridge Source: See RDCHEM.RAW Data loads lazily.
data('rdtelec')A data.frame with 29 observations on 6 variables:
rd: R&D spending, millions $
sales: firm sales, millions $
rdintens: rd as percent of sales
lrd: log(rd)
lsales: log(sales)
salessq: sales^2
https://www.cengage.com/cgi-wadsworth/course_products_wp.pl?fid=M20b&product_isbn_issn=9781111531041
According to these data, the R&D/firm size relationship is different in the telecommunications industry than in the chemical industry: there is pretty strong evidence that R&D intensity decreases with firm size in telecommunications. Of course, that was in 1991. The data could easily be updated, and a panel data set could be constructed.
Used in Text: not used
str(rdtelec)
#> 'data.frame': 29 obs. of 6 variables:
#> $ rd : num 25.5 2433 5.7 1.7 41 ...
#> $ sales : num 259.8 37285 47.9 35.7 14345.4 ...
#> $ rdintens: num 9.815 6.525 11.9 4.762 0.286 ...
#> $ lrd : num 3.239 7.797 1.74 0.531 3.714 ...
#> $ lsales : num 5.56 10.53 3.87 3.58 9.57 ...
#> $ salessq : num 6.75e+04 1.39e+09 2.29e+03 1.27e+03 2.06e+08 ...
#> - attr(*, "time.stamp")= chr "25 Jun 2011 23:03"