how to make an index by time series data

[ecofine]

Dear Friends,

I wish to make an index for a series of data such as panel data (time x cross).
If there 20 years of data of 15 number of firms from 1980 to 2000, I wish to make the year of 1990 as of indexing year;
so all data will be divided by the data of 1990. Could kindly let me know how to make this changes?


firm#1 1981 x1-1
#1 1982 x1-2;
;
#1 1990 x1-10 => base year
;

#1 2000 x1-20

firm #2 1981 x2-1

#2 1982 x2-2;
;
#2 1990 x2-10; base year
;

#2 2000 x2-20

etc

To convert these data by the base year of 1990; all panel data will be indexed on 1990

for example,
for #1
1981 (x1-1/x1-10)*100

1990 (x1-10/x1-10)*100 = 100

2000 x1-20/x1-10

for #2
1981 (x2-1/x2-10)*100

1990 (x1-10/x2-10)*100 = 100

2000 (x2-20/x2-10)*100

etc

I don't know how to fix the year of 1990 and use indexing for panel data as mentioned above.

Your kind answer is very helpful!

Thank you.

Insang

[EViews Gareth]

Assuming you have annual data, you can do:

Code: Select all

series y1= x1/@meansby(x1, @crossid, "1990 1990")