# [no subject]

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> I don't see how anyone can comment on the previous
> post mentioned so vaguely.
>
> Forgetting the panel aspect for a moment,
>
> gen K = k
> replace K = 0.95 * K[_n-1] + I in 2/l
>
> That is, you initialise a variable and
> then -replace- all the first value.
> [_n-1] is Stata's way of referring to
> the previous value.
>
> Now reinserting the panel aspect, you
> need to work
>
> by firm:
>
> but -by:- won't let you work with -in-.
>
> gen K = k
> bysort firm (year) : replace K = 0.95 * K[_n-1] + I if _n > 1
>
> should be closer to what you want.
>
> If you -tsset-, the solution would be better as
>
> tsset firm year
> gen K = k
> by firm: replace K = 0.95 * L.K + I if _n > 1
>
> Nick
> [email protected]
>
> Damiano Rossi
>
> I need some help to compute a capital stock series from a gross
> investment series. My primary problem is that I have to estimate the
> initial capital stock (K_0 ) for each firm. As a general rule, it is
> used the book value of fixed capital (K) in the first year of data (e.g.
> 1996) for each firm. How can I command Stata to consider this first
> observation (firm by firm) and then compute a capital stock series,
> using a perpetual inventory and a constant rate of depreciation? A
> previous post doesn't help me much on this point. These are the data.
>
> Panl oif 300 firms, 10 years (1996-2006)
> k = capital stock
> I = capital investment
> d [delta] = 0.05
>
> The evolution of the real capital stock is:
> K_t+i = (1 - d)*K_t+i-1 + I_t+i
>
>
> *
> *   For searches and help try:
> *   http://www.stata.com/support/faqs/res/findit.html
> *   http://www.stata.com/support/statalist/faq
> *   http://www.ats.ucla.edu/stat/stata/
>

*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/
```