A set of typical indexes is very useful in adjusting a sales series, for example, for seasonal fluctuations. The resulting sales series is called depersonalized sales or seasonally adjusted sales. The reason for depersonalizing the sales series is to remove the seasonal fluctuations so that the trend and cycle can be studied. To illustrate the procedure, the quarterly sales totals of Toys International from Table 16-6 are repeated in column 1 of Table 16-9.
TABLE 16-9 Actual and Depersonalized Sales for Toys International
|
|
-1
|
-2
|
-3
|
|
|
|
|
Seasonal Index
|
Deseasonalized Sales
|
|
Year
|
Quarter
|
Sales
|
|
|
|
2004
|
Winter
|
6.7
|
0.765
|
8.76
|
|
Spring
|
4.6
|
0.575
|
8
|
|
Summer
|
10
|
1.141
|
8.76
|
|
Fall
|
12.7
|
1.519
|
8.36
|
|
2005
|
Winter
|
6.5
|
0.765
|
8.5
|
|
Spring
|
4.6
|
0.575
|
8
|
|
Summer
|
9.8
|
1.141
|
8.59
|
|
Fall
|
13.6
|
1.519
|
8.95
|
|
2006
|
Winter
|
6.9
|
0.765
|
9.02
|
|
Spring
|
5
|
0.575
|
8.7
|
|
Summer
|
10.4
|
1.141
|
9.11
|
|
Fall
|
14.1
|
1.519
|
9.28
|
|
2007
|
Winter
|
7
|
0.765
|
9.15
|
|
Spring
|
5.5
|
0.575
|
9.57
|
|
Summer
|
10.8
|
1.141
|
9.47
|
|
Fall
|
15
|
1.519
|
9.87
|