Re: st: shifting data inside panel data

[Jorge Eduardo Pérez Pérez <perez.jorge@ur.edu.co>]

Sounds like

reshape wide price quantity, i(week product_id) j(store)

_______________________
Jorge Eduardo Pérez Pérez


On Fri, May 4, 2012 at 3:37 AM, Tomáš Houška <xbender@gmail.com> wrote:
> Dear Statalist,
>
> I have panel data of the following structure: "Store - Week -
> Product_ID - Price - Quantity". Where there are multiple week data for
> each store and multiple products being sold in each store every week.
> Overall I have 36 stores, 28 products and 220 weeks, the data are in a
> long format. The dataset is symmetric - all products were sold in
> every store and in every week.
>
> I am trying to create a new variable (lets call it "price_iv"), which
> will be an instrumental variable for my demand analysis. I would like
> the variable to contain for each product in each week prices from a
> different store - i.e. I would like to shift the price data in the
> "price" variable in such a way, that price of a product 1 in week one
> and store 1 will correspond to the prices of product 1 in week in and
> store 2 (or any other). Optimally each store will be used only once -
> so at the end the data from all stores would be assigned to a
> different store.
> I havent been able to come up with a way, how to shift the data in an
> appropriate way - Can you please help me solve this problem?
>
> Thank you !
> Tomas
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>


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