gamlss.data (version 4.3-4)

polio: Poliomyelitis cases in US

Description

Poliomyelitis cases reported to the U.S. Centers for Disease Control for the years 1970 to 1983, that is, 168 observations.

Usage

data(polio)

Format

The format is: Time-Series [1:168] from 1970 to 1984: 0 1 0 0 1 3 9 2 3 5 ...

Source

Zeger (1988) w

Details

The data were originally modelled by Zeger (1988) who used a parameter driven approach, in which a first order autoregressive model was used for the latent process, to conclude that there is evidence of a decrease in the polio infection rate. The data were analysed also by Li (1994), Zeger and Qaqish (1988), Davis et al. (1999), and by Benjamin et al (2003).

References

Benjamin M. A., Rigby R. A. and Stasinopoulos D.M. (2003) Generalised Autoregressive Moving Average Models. J. Am. Statist. Ass., 98, 214-223.

Davis, R. A., Dunsmuir, W. T. M. and Wang, Y. (1999), ``Modelling Time Series of Count Data,'' in Asymptotics, Nonparametrics and Time Series (ed Subir Ghosh): Marcel Dekker

Zeger, S. L. (1988), ``A Regression Model for Time Series of Counts,'' Biometrika, 75, 822-835.

Zeger, S. L. and Qaqish, B. (1988), ``Markov Regression Models for Time Series: A Quasi-likelihood Approach,'' Biometrics, 44, 1019-1032.

Examples

data(polio)
plot(polio)