EquipmentR Documentation

Transportation Equipment Manufacturing Data

Description

Statewide data on transportation equipment manufacturing for 25 US states.

Usage

data("Equipment")

Format

A data frame containing 25 observations on 4 variables.

valueadded

Aggregate output, in millions of 1957 dollars.

capital

Capital input, in millions of 1957 dollars.

labor

Aggregate labor input, in millions of man hours.

firms

Number of firms.

Source

Journal of Applied Econometrics Data Archive.

http://qed.econ.queensu.ca/jae/1998-v13.2/zellner-ryu/

Online complements to Greene (2003), Table F9.2.

http://pages.stern.nyu.edu/~wgreene/Text/tables/tablelist5.htm

References

Greene, W.H. (2003). Econometric Analysis, 5th edition. Upper Saddle River, NJ: Prentice Hall.

Zellner, A. and Revankar, N. (1969). Generalized Production Functions. Review of Economic Studies, 36, 241–250.

Zellner, A. and Ryu, H. (1998). Alternative Functional Forms for Production, Cost and Returns to Scale Functions. Journal of Applied Econometrics, 13, 101–127.

See Also

Greene2003

Examples

## Greene (2003), Example 17.5
data("Equipment")

## Cobb-Douglas
fm_cd <- lm(log(valueadded/firms) ~ log(capital/firms) + log(labor/firms), data = Equipment)

## generalized Cobb-Douglas with Zellner-Revankar trafo
GCobbDouglas <- function(theta)
 lm(I(log(valueadded/firms) + theta * valueadded/firms) ~ log(capital/firms) + log(labor/firms), 
     data = Equipment)

## yields classical Cobb-Douglas for theta = 0
fm_cd0 <- GCobbDouglas(0)

## ML estimation of generalized model
## choose starting values from classical model
par0 <- as.vector(c(coef(fm_cd0), 0, mean(residuals(fm_cd0)^2)))

## set up likelihood function
nlogL <- function(par) {
  beta <- par[1:3]
  theta <- par[4]
  sigma2 <- par[5]

  Y <- with(Equipment, valueadded/firms)
  K <- with(Equipment, capital/firms)
  L <- with(Equipment, labor/firms)

  rhs <- beta[1] + beta[2] * log(K) + beta[3] * log(L)
  lhs <- log(Y) + theta * Y

  rval <- sum(log(1 + theta * Y) - log(Y) +
    dnorm(lhs, mean = rhs, sd = sqrt(sigma2), log = TRUE))
  return(-rval)
}

## optimization
opt <- optim(par0, nlogL, hessian = TRUE)

## Table 17.2
opt$par
sqrt(diag(solve(opt$hessian)))[1:4]
-opt$value

## re-fit ML model
fm_ml <- GCobbDouglas(opt$par[4])
deviance(fm_ml)
sqrt(diag(vcov(fm_ml)))

## fit NLS model
rss <- function(theta) deviance(GCobbDouglas(theta))
optim(0, rss)
opt2 <- optimize(rss, c(-1, 1))
fm_nls <- GCobbDouglas(opt2$minimum)
-nlogL(c(coef(fm_nls), opt2$minimum, mean(residuals(fm_nls)^2)))