The "weighting matrix.csv" file has the spatial weighting matrix that is 
used in the regression.

The "zillow-data.csv" file has all the necessary variables. The first 
row is the variable names. Most variables names are easy to understand. 
Several variable names below need clarification.

CName: county name;
HPI: housing price index;
Pop: population;
IPI: industrial production index;
MorRate: morgage interest rate;
RHPI: real housing price index (deflated by CPI);
lHPI : the natural log of RHPI;
lHPI_1: one month lag of lHPI;
lHPI_2: two-month lag of lHPI;
lead1_lHPI: one month lead of lHPI;
lead2_lHPI: two-month lead of lHPI.
