  Since the beginning of the corona pandemic in March 2020, various parameters
for describing the spread of the disease have been specified for Germany in
addition to the daily infection figures (new infections and total infections),
which are also used for political decisions. In addition to excess mortality
and the weekly incidence, these include the doubling time $T_2$ and the
reproduction number $R_t$. For the latter, various estimates can be found on
the website of the Robert-Koch-Institute, see \cite{EstR:RKI}, which are
calculated from the case numbers for all of Germany; local differences are not
taken into account here. In the present article, the calculations of the RKI on
a local level are examined using the example of northern Rhineland-Palatinate
and its districts. Here, not the reporting date but the onset of illness is
used as a reference for the calculation of $R_t$. For cases where the onset of
illness is not known, an adjusted generalized extreme value distribution (GEV)
is first fitted to the data for which the reporting delay (difference between
the onset of illness and the reporting date) is available and examined for
further characteristics such as local as well as demographic differences. This
GEV distribution is then used to calculate the reporting delays of incomplete
data points. The calculation of the daily value of $R_t$ between the end of
February and the end of October showed a similar course of the reproductive
rate compared to the nationwide figures. Expectably larger statistical
fluctuations were observed in the summer, mainly due to lower case numbers. The
values for northern Rhineland-Palatinate have been consistently above $1$ since
about mid-September. The calculations can also be transferred to other regions
and administrative districts.
