wallace.iowaland {agridat} | R Documentation

## Iowa farmland values by county in 1925

### Description

Iowa farmland values by county in 1925

### Usage

    data("wallace.iowaland")

### Format

A data frame with 99 observations on the following 10 variables.

`county`

  county factor, 99 levels

`fips`

  FIPS code (state+county)

`lat`

  latitude

`long`

  longitude

`yield`

  average corn yield per acre (bu)

`corn`

  percent of land in corn

`grain`

  percent of land in small grains

`untillable`

  percent of land untillable

`fedval`

  land value (excluding buildings) per acre, 1925 federal census

`stval`

  land value (excluding buildings) per acre, 1925 state census

### Details

None.

### Source

H.A. Wallace (1926). Comparative Farm-Land Values in Iowa. The Journal of Land & Public Utility Economics, 2, 385-392. Page 387-388. http://doi.org/10.2307/3138610

### References

Larry Winner. Spatial Data Analysis. http://www.stat.ufl.edu/~winner/data/iowaland.txt

### Examples

    data(wallace.iowaland)
    dat <- wallace.iowaland

    # Interesting trends involving latitude
    require(lattice)
    splom(~dat[,-c(1:2)], type=c('p','smooth'), lwd=2, main="wallace.iowaland")

    # Means. Similar to Wallace table 1
    apply(dat[, c('yield','corn','grain','untillable','fedval')], 2, mean)

    # Correlations.  Similar to Wallace table 2
    round(cor(dat[, c('yield','corn','grain','untillable','fedval')]),2)

    m1 <- lm(fedval ~ yield + corn + grain + untillable, dat)
    summary(m1) # estimates similar to Wallace, top of p. 389

    # Choropleth map
    require(maps)
    data(county.fips)
    dat <- transform(dat, polnm = paste0('iowa,',county)) # polnm example: iowa,adair

    if(require("latticeExtra")){ # for mapplot
      redblue <- colorRampPalette(c("firebrick", "lightgray", "#375997"))
      mapplot(polnm~fedval , data=dat, colramp=redblue,
              main="wallace.iowaland - Federal land values",
              xlab="Land value, dollars per acre",
              scales=list(draw=FALSE),
              map=map('county', 'iowa', plot=FALSE,
                fill=TRUE, projection="mercator"))
    }

[Package agridat version 1.16 Index]