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From |
Nick Cox <njcoxstata@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: How to generate an index for the calculation of geometric mean |

Date |
Tue, 11 Dec 2012 10:03:14 +0000 |

You are correct; you wrote 2, 3. But why count repeated 25s but not repeated 1s? There can be no code without a logic to how you are counting. Nick On Tue, Dec 11, 2012 at 9:57 AM, Yuval Arbel <yuval.arbel@gmail.com> wrote: > It's not 2.3 but rather t=1 for reduct_per==25, t=2 for > reduct_per==625, t=3 for reduct_per==15625 etc, so that when I > calculate 625^(1/2) and 15625^(1/3) I get 25 > > On Tue, Dec 11, 2012 at 11:46 AM, Nick Cox <njcoxstata@gmail.com> wrote: >> I didn't understand what you want when you asked this yesterday, and >> the same applies to this repetition. Specifically, where does the 2.3 >> come from? Please show the formula which produces this result. >> >> Nick >> >> On Tue, Dec 11, 2012 at 7:31 AM, Yuval Arbel <yuval.arbel@gmail.com> wrote: >> >>> I would like to generate an index variable for the calculation of the >>> geometrical mean of an unbalanced panel (namely, the exponent, which >>> makes the product a >>> geometrical mean). >>> >>> Here is an example of one panel: >>> >>> . list reduct_per y3 if appt==2862 >>> >>> +---------------------+ >>> | reduct~r y3 | >>> |---------------------| >>> 30. | 1 1 | >>> 31. | 1 1 | >>> 32. | 1 1 | >>> 33. | 1 1 | >>> 34. | 1 1 | >>> |---------------------| >>> 35. | 1 1 | >>> 36. | 1 1 | >>> 37. | 1 1 | >>> 38. | 1 1 | >>> 39. | 1 1 | >>> |---------------------| >>> 40. | 1 1 | >>> 41. | 1 1 | >>> 42. | 1 1 | >>> 43. | 1 1 | >>> 44. | 1 1 | >>> |---------------------| >>> 45. | 1 1 | >>> 46. | 1 1 | >>> 47. | 1 1 | >>> 48. | 1 1 | >>> 49. | 1 1 | >>> |---------------------| >>> 50. | 1 1 | >>> 51. | 1 1 | >>> 52. | 1 1 | >>> 53. | 1 1 | >>> 54. | 1 1 | >>> |---------------------| >>> 55. | 25 25 | >>> 56. | 25 625 | >>> 57. | 25 15625 | >>> 58. | 25 390625 | >>> 59. | 25 9765625 | >>> |---------------------| >>> 60. | 25 2.44e+08 | >>> 61. | 25 6.10e+09 | >>> 62. | 25 1.53e+11 | >>> 63. | 25 3.81e+12 | >>> 64. | 25 9.54e+13 | >>> |---------------------| >>> 65. | 25 2.38e+15 | >>> 66. | 25 5.96e+16 | >>> +---------------------+ >>> >>> >>> The problem is that for reduct_per==1 I would like >>> the index to become a constant and remain the same until the next >>> reduct_per, which is different from zero, comes. >>> >>> Consider the example above: during the first 26 periods the index >>> should be one and and starting from the 26th period it should change >>> to 2,3 etc. >>> >>> If, on the other hand, we would have opposite descending trail (namely >>> 25 percent reduction rate from 1-25 and zero starting from the 26th >>> period), the index should be 1, 2,..,25 and then becomes a constant 25 from >>> the 26th period. >>> >>> What is the simplest way to generate such an index? Can it be done >>> without a loop? * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/

**References**:**st: How to generate an index for the calculation of geometric mean***From:*Yuval Arbel <yuval.arbel@gmail.com>

**Re: st: How to generate an index for the calculation of geometric mean***From:*Nick Cox <njcoxstata@gmail.com>

**Re: st: How to generate an index for the calculation of geometric mean***From:*Yuval Arbel <yuval.arbel@gmail.com>

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