NBER isn't good at models

good_modelz.R

# data digitized from https://twitter.com/nberpubs/status/1062080096549261312
# thanks @tpoi and co! https://cran.r-project.org/web/packages/digitize/index.html

# load the above data
dat <- read.csv("nber.csv")

# it's ya boi, mgcv
library(mgcv)

# fit the next stupidest model
b <- gam(y~s(x), data=dat)

# make predictions for plotting, incl uncertainty
preddat <- data.frame(x=seq(min(dat$x), max(dat$x), len=200))
pred <- predict(b, preddat, se=TRUE, unconditional=TRUE)
preddat$y <- pred$fit
# make +/- 2 std errors
preddat$upper <- pred$fit + 2*pred$se
preddat$lower <- pred$fit - 2*pred$se

# make a plotto
plot(dat, xlab="90th percentile-earner personal-income marginal tax rate(%)", ylab="log patents", type="n")
polygon(c(preddat$upper, rev(preddat$lower)),
        x=c(preddat$x, rev(preddat$x)),
        border=FALSE, col=grey(.8))
lines(preddat$x, preddat$y)
points(dat, pch=19, cex=0.6)

nber.csv

The resulting plot: