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Price change and volume change (Price Elasticity Concept)

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Contributor
Posts: 29

Price change and volume change (Price Elasticity Concept)

[ Edited ]

Hi,

 

I have table like as shown below:

 

Prod_ID Date SP Vol
101 01Jan2015 18 50
101 04Jan2015 19 55
101 07Jan2015 20 40
101 12Jan2015 19 53
101 15Jan2015 20 37
101 19Jan2015 18 52
101 24Jan2015 19 54
101 25Jan2015 21 32
101 29Jan2015 18 51
101 31Jan2015 20 42
102 01Jan2015 9 40
102 04Jan2015 10 35
102 07Jan2015 8 45
102 12Jan2015 7 44
102 15Jan2015 9 42
102 19Jan2015 11 39
102 24Jan2015 8 48
102 25Jan2015 11 41
102 29Jan2015 9 45
102 31Jan2015 10 36

 

 

Now i need to calculate price change and volume change:

 

The formula used to calculate the percentage change in SP is:
Price Change= [SP(NEW) - SP(OLD)] / SP(OLD)

The formula used to calculate the percentage change in Vol is:
Volume Change=[Vol(NEW) - Vol(OLD)] / Vol(OLD) 

 

Elasticity= Price Change/Volume Change

 

So my result should be:

 

Prod_ID Date SP Vol Price Change Volume Change Elasticity
101 01Jan2015 18 50 0 0 0
101 04Jan2015 19 55 0.055555556 0.1 1.8
101 07Jan2015 20 40 0.052631579 -0.272727273 -5.181818182
101 12Jan2015 19 53 -0.05 0.325 -6.5
101 15Jan2015 20 37 0.052631579 -0.301886792 -5.735849057
101 19Jan2015 18 52 -0.1 0.405405405 -4.054054054
101 24Jan2015 19 54 0.055555556 0.038461538 0.692307692
101 25Jan2015 21 32 0.105263158 -0.407407407 -3.87037037
101 29Jan2015 18 51 -0.142857143 0.59375 -4.15625
101 31Jan2015 20 42 0.111111111 -0.176470588 -1.588235294
102 01Jan2015 9 40 0 0 0
102 04Jan2015 10 35 0.111111111 -0.125 -1.125
102 07Jan2015 8 45 -0.2 0.285714286 -1.428571429
102 12Jan2015 7 44 -0.125 -0.022222222 0.177777778
102 15Jan2015 9 42 0.285714286 -0.045454545 -0.159090909
102 19Jan2015 11 39 0.222222222 -0.071428571 -0.321428571
102 24Jan2015 8 48 -0.272727273 0.230769231 -0.846153846
102 25Jan2015 11 41 0.375 -0.145833333 -0.388888889
102 29Jan2015 9 45 -0.181818182 0.097560976 -0.536585366
102 31Jan2015 10 36 0.111111111 -0.2 -1.8

 

I also have doubt whether this is the approach to do price elasticity? Please share your thoughts on this

 

Thanks 

Ganesh K

Super User
Posts: 17,750

Re: Price change and volume change (Price Elasticity Concept)

What is your question? Do you need help implementing the formula's in SAS? Or with the methodology of your problem, which would be considered out of scope for this forum.  

Super User
Posts: 9,662

Re: Price change and volume change (Price Elasticity Concept)

I am familiar with these concepts .



data have;
infile cards truncover expandtabs;
input Prod_ID	Date : $20.	SP	Vol;
cards;
101	01Jan2015	18	50
101	04Jan2015	19	55
101	07Jan2015	20	40
101	12Jan2015	19	53
101	15Jan2015	20	37
101	19Jan2015	18	52
101	24Jan2015	19	54
101	25Jan2015	21	32
101	29Jan2015	18	51
101	31Jan2015	20	42
102	01Jan2015	9	40
102	04Jan2015	10	35
102	07Jan2015	8	45
102	12Jan2015	7	44
102	15Jan2015	9	42
102	19Jan2015	11	39
102	24Jan2015	8	48
102	25Jan2015	11	41
102	29Jan2015	9	45
102	31Jan2015	10	36
;
run;
data want;
 set have;
 by Prod_ID;
 PriceChange=(SP-lag(SP))/lag(SP);
 VolumeChange=(Vol-lag(Vol))/lag(Vol);
 Elasticity= PriceChange/VolumeChange;
 if first.Prod_ID then do;
  PriceChange=0;
  VolumeChange=0;
  Elasticity=0;
 end;
run;


Contributor
Posts: 29

Re: Price change and volume change (Price Elasticity Concept)

Hi Ksharp,

 

Thanks for code. I need to know is this the method used to arrive Price elasticity? Since i am new to work on this concept. I went through this link : http://support.sas.com/rnd/app/examples/ets/simpelast/sas.htm 

 

Do i need to consider some of other factor?

 

Overall i want to know how to arrive Price elasticity?

 

Thanks,

Ganesh K

Super User
Posts: 9,662

Re: Price change and volume change (Price Elasticity Concept)

Sorry. I can not understand what you mean. Maybe you should start another new session to discuss this topic.
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