Last data update: 2014.03.03

R: Black and White Pepper Prices
PepperPriceR Documentation

Black and White Pepper Prices

Description

Time series of average monthly European spot prices for black and white pepper (fair average quality) in US dollars per ton.

Usage

data("PepperPrice")

Format

A monthly multiple time series from 1973(10) to 1996(4) with 2 variables.

black

spot price for black pepper,

white

spot price for white pepper.

Source

Online complements to Franses (1998).

http://www.few.eur.nl/few/people/franses/research/book2.htm

References

Franses, P.H. (1998). Time Series Models for Business and Economic Forecasting. Cambridge, UK: Cambridge University Press.

Examples

## data
data("PepperPrice")
plot(PepperPrice, plot.type = "single", col = 1:2)

## package
library("tseries")
library("urca")

## unit root tests
adf.test(log(PepperPrice[, "white"]))
adf.test(diff(log(PepperPrice[, "white"])))
pp.test(log(PepperPrice[, "white"]), type = "Z(t_alpha)")
pepper_ers <- ur.ers(log(PepperPrice[, "white"]),
  type = "DF-GLS", model = "const", lag.max = 4)
summary(pepper_ers)

## stationarity tests
kpss.test(log(PepperPrice[, "white"]))

## cointegration
po.test(log(PepperPrice))
pepper_jo <- ca.jo(log(PepperPrice), ecdet = "const", type = "trace")
summary(pepper_jo)
pepper_jo2 <- ca.jo(log(PepperPrice), ecdet = "const", type = "eigen")
summary(pepper_jo2)

Results


R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

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Type 'demo()' for some demos, 'help()' for on-line help, or
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> library(AER)
Loading required package: car
Loading required package: lmtest
Loading required package: zoo

Attaching package: 'zoo'

The following objects are masked from 'package:base':

    as.Date, as.Date.numeric

Loading required package: sandwich
Loading required package: survival
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/AER/PepperPrice.Rd_%03d_medium.png", width=480, height=480)
> ### Name: PepperPrice
> ### Title: Black and White Pepper Prices
> ### Aliases: PepperPrice
> ### Keywords: datasets
> 
> ### ** Examples
> 
> ## data
> data("PepperPrice")
> plot(PepperPrice, plot.type = "single", col = 1:2)
> 
> ## package
> library("tseries")
> library("urca")
> 
> ## unit root tests
> adf.test(log(PepperPrice[, "white"]))

	Augmented Dickey-Fuller Test

data:  log(PepperPrice[, "white"])
Dickey-Fuller = -1.744, Lag order = 6, p-value = 0.6838
alternative hypothesis: stationary

> adf.test(diff(log(PepperPrice[, "white"])))

	Augmented Dickey-Fuller Test

data:  diff(log(PepperPrice[, "white"]))
Dickey-Fuller = -5.336, Lag order = 6, p-value = 0.01
alternative hypothesis: stationary

Warning message:
In adf.test(diff(log(PepperPrice[, "white"]))) :
  p-value smaller than printed p-value
> pp.test(log(PepperPrice[, "white"]), type = "Z(t_alpha)")

	Phillips-Perron Unit Root Test

data:  log(PepperPrice[, "white"])
Dickey-Fuller Z(t_alpha) = -1.6439, Truncation lag parameter = 5,
p-value = 0.726
alternative hypothesis: stationary

> pepper_ers <- ur.ers(log(PepperPrice[, "white"]),
+   type = "DF-GLS", model = "const", lag.max = 4)
> summary(pepper_ers)

############################################### 
# Elliot, Rothenberg and Stock Unit Root Test # 
############################################### 

Test of type DF-GLS 
detrending of series with intercept 


Call:
lm(formula = dfgls.form, data = data.dfgls)

Residuals:
     Min       1Q   Median       3Q      Max 
-0.21135 -0.03069 -0.00108  0.03030  0.31018 

Coefficients:
              Estimate Std. Error t value Pr(>|t|)    
yd.lag       -0.004022   0.006015  -0.669    0.504    
yd.diff.lag1  0.336267   0.061986   5.425 1.32e-07 ***
yd.diff.lag2 -0.105024   0.065414  -1.606    0.110    
yd.diff.lag3  0.001263   0.065366   0.019    0.985    
yd.diff.lag4  0.011251   0.062085   0.181    0.856    
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 0.06481 on 261 degrees of freedom
Multiple R-squared:  0.1028,	Adjusted R-squared:  0.0856 
F-statistic:  5.98 on 5 and 261 DF,  p-value: 2.947e-05


Value of test-statistic is: -0.6686 

Critical values of DF-GLS are:
                 1pct  5pct 10pct
critical values -2.57 -1.94 -1.62

> 
> ## stationarity tests
> kpss.test(log(PepperPrice[, "white"]))

	KPSS Test for Level Stationarity

data:  log(PepperPrice[, "white"])
KPSS Level = 0.91295, Truncation lag parameter = 3, p-value = 0.01

Warning message:
In kpss.test(log(PepperPrice[, "white"])) :
  p-value smaller than printed p-value
> 
> ## cointegration
> po.test(log(PepperPrice))

	Phillips-Ouliaris Cointegration Test

data:  log(PepperPrice)
Phillips-Ouliaris demeaned = -24.099, Truncation lag parameter = 2,
p-value = 0.02404

> pepper_jo <- ca.jo(log(PepperPrice), ecdet = "const", type = "trace")
> summary(pepper_jo)

###################### 
# Johansen-Procedure # 
###################### 

Test type: trace statistic , without linear trend and constant in cointegration 

Eigenvalues (lambda):
[1] 4.931953e-02 1.350807e-02 2.081668e-17

Values of teststatistic and critical values of test:

          test 10pct  5pct  1pct
r <= 1 |  3.66  7.52  9.24 12.97
r = 0  | 17.26 17.85 19.96 24.60

Eigenvectors, normalised to first column:
(These are the cointegration relations)

           black.l2 white.l2   constant
black.l2  1.0000000  1.00000   1.000000
white.l2 -0.8892307 -5.09942   2.280911
constant -0.5569943 33.02742 -20.032441

Weights W:
(This is the loading matrix)

           black.l2    white.l2      constant
black.d -0.07472300 0.002453210 -4.958157e-18
white.d  0.02015611 0.003537005  8.850353e-18

> pepper_jo2 <- ca.jo(log(PepperPrice), ecdet = "const", type = "eigen")
> summary(pepper_jo2)

###################### 
# Johansen-Procedure # 
###################### 

Test type: maximal eigenvalue statistic (lambda max) , without linear trend and constant in cointegration 

Eigenvalues (lambda):
[1] 4.931953e-02 1.350807e-02 2.081668e-17

Values of teststatistic and critical values of test:

          test 10pct  5pct  1pct
r <= 1 |  3.66  7.52  9.24 12.97
r = 0  | 13.61 13.75 15.67 20.20

Eigenvectors, normalised to first column:
(These are the cointegration relations)

           black.l2 white.l2   constant
black.l2  1.0000000  1.00000   1.000000
white.l2 -0.8892307 -5.09942   2.280911
constant -0.5569943 33.02742 -20.032441

Weights W:
(This is the loading matrix)

           black.l2    white.l2      constant
black.d -0.07472300 0.002453210 -4.958157e-18
white.d  0.02015611 0.003537005  8.850353e-18

> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>