McSpatial (version 2.0)

repsaledata: Preparation of a Repeat Sales Data Set

Description

Identifies repeat sales from a data set with observations on sale price, time of sale, and a property id. Returns a data frame in which each observation is a repeat sales pair.

Usage

repsaledata(price,timevar,id)

Arguments

price

Variable representing sale price

timevar

Variable representing date of sale

id

Property id

Value

id

Property id

price0

Sale price at earlier date

time0

Earlier sales date

price1

Sale price at later date

time1

Later sales date

Details

The input to repsaledata is meant to be a set of variables from a standard hedonic data set -- the sale price, date, and an id number for the individual property. The function identifies the subset of properties that sold at least twice and forms a new data set in which each observation is a repeat sales pair, with "0" denoting the earlier time and "1" denoting the later date in the variable names. The observations are ordered first by id, then by timevar, and then by price. A repeat sales pair is formed by matching an observation for which id(t)=id(t-1) and timevar(t)=timevar(t-1). Thus, a property that sold in times 1, 2, and 3 will produce 2 repeat sales pairs: (1) t = 1 and 2, and (2) t = 2 and 3.

The output of repsaledata is a data frame with 5 variables. If some of the original hedonic data set variables need to be included in the repeat sales data set, the original hedonic data set and the repsaledata data frame can be merged by the id variable.

See Also

repsale

repsalefourier

repsaleqreg

Examples

id <-      c(1,1,1, 2,2,2, 3,3,3, 4,4,4, 5,5,5)
timevar <- c(1,2,3, 1,2,2, 3,1,1, 1,1,2, 2,2,3)
price <- seq(1:15)
basedata <- data.frame(id,timevar,price)
basedata

rdata <- repsaledata(price,timevar,id)
rdata