A survey was conducted in April 1993 by Infratest Sozialforschung.
A random sample of accommodation with new tenancy agreements or
increases of rents within the last four years in Munich was
selected including: i) single rooms, ii) small apartments, iii)
flats, iv) two-family houses. Accommodation subject to price
control rents, one family houses and special houses, such as
penthouses, were excluded because they are rather different from
the rest and are considered a separate market. For the purpose of
this study, 1967 observations of the variables listed below were
used, i.e. the rent response variable R followed by the
explanatory variables found to be appropriate for a regression
analysis approach by Fahrmeir *et al.* (1994, 1995):

`data(rent)`

A data frame with 1969 observations on the following 9 variables.

- R
: rent response variable, the monthly net rent in DM, i.e. the monthly rent minus calculated or estimated utility cost

- Fl
: floor space in square meters

- A
: year of construction

- Sp
: a variable indicating whether the location is above average,

`1`

, (550 observations) or not,`0`

, (1419 observations)- Sm
: a variable indicating whether the location is below,

`1`

, average (172 obs.) or not,`0`

, (1797 obs.)- B
: a factor with levels indicating whether there is a bathroom,

`1`

, (1925 obs.) or not,`0`

, (44 obs.)- H
: a factor with levels indicating whether there is central heating,

`1`

, (1580 obs.) or not,`0`

, (389 obs.)- L
: a factor with levels indicating whether the kitchen equipment is above average,

`1`

, (161 obs.) or not,`0`

, (1808 obs.)- loc
: a factor (combination of Sp and Sm) indicating whether the location is below,

`1`

, average,`2`

, or above average`3`

This set of data were used by Stasinopoulos *et al.* (2000) to fit a model where both the mean
and the dispersion parameter of a Gamma distribution were modelled using the explanatory variables.

Fahrmeir L., Gieger C., Mathes H. and Schneeweiss H. (1994) Gutachten zur Erstellung des Mietspiegels fur Munchen 1994, Teil B: Statistiche Analyse der Nettomieten. Hrsg: Landeshaupttstadt Munchen, Sozialreferat-Amt fur Wohnungswesen.

Fahrmeir L., Gieger C., and Klinger, A. (1995) Additive,
dynamic and multiplicative regression. In * Applied Statistics:
Recent Developments*, Vandenhoeck and Ruprecht, Gottingen.

Stasinopoulos, D. M., Rigby, R. A. and Fahrmeir, L., (2000),
Modelling rental guide data using mean and dispersion additive models, *Statistician*, **49 **,
479-493.

Stasinopoulos D. M. Rigby R.A. (2007) Generalized additive models for location scale and shape (GAMLSS) in R.
*Journal of Statistical Software*, Vol. **23**, Issue 7, Dec 2007, tools:::Rd_expr_doi("10.18637/jss.v023.i07").

```
data(rent)
attach(rent)
plot(Fl,R)
```

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