A spatial-temporal Markov random-field model is used to produce indices for
residential real estate from repeat home sale data. A set of regions is re
presented by a graph in which neighboring regions are linked. This graph. r
epeated consecutively a number of times, with each region linked to the sam
e region at adjacent times, defines a spatial-temporal graph that connects
regions over space and time in which each node represents a region at a par
ticular time. An index is defined at each node to be the rate of appreciati
on of log sale price in a region during the preceding time interval. The in
dices are estimated from data consisting of repeat home sales. The Markov r
andom-field model specifies spatial and temporal correlations between neigh
boring indices and relations between indices and individual repeat sales. A
method is proposed for estimating various parameters in the model and for
obtaining real-estate indices. Following this prescription. indices are cal
culated for the Dade County, Florida, residential real-estate market. Resul
ts are compared to those obtained using competing space-only models.