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How do you think that decisions are made under uncertainty? You can't always wait until you have very solid numbers to come up with an analysis. It's not "ridic

How do you think that decisions are made under uncertainty? You can't always wait until you have very solid numbers to come up with an analysis. It's not "ridiculous" to come up with an order of magnitude estimate when better information is unavailable, it's a critical step in solving new problems. A more productive criticism would have been to offer an improvement, rather than to just point to the imperfections in an attempt to estimate the future impact of a new technology. edit: added second paragraph

honkhonkpants 10y ago
OK, but in 2016 we don't have to guess how many cars Tesla built in 2015. It's historical fact.
- shawn-furyan 10y ago
  What is it? You could actually improve the estimate rather than /just/ pointing out that it has flaws. And your original criticism was vague. At least this one moves things forward. After a quick Google search, the number of vehicles Tesla sold in 2015 does in fact seem to be a bit uncertain. It seems they sold over 50,000 vehicles, but I've not found a more precise number, in a few minutes of looking. Sales from previous years seem to be: 2012 - 2,650 2013 - 22,477 2014 - 31,655 2015- ~50,000 though I got these numbers from a quora post, so take them with an adequately large dose of salt. edit: added google findings, tweaked wording to be more specific
  - honkhonkpants 10y ago
    There is no reason to guess at these numbers OR to Google for other people's guesses. The sales figures to 5 significant digits are in Tesla's 10-K report. For example: During 2015, we achieved significant efficiencies in Model S production and produced 14,037 vehicles in the fourth quarter of 2015. We began production of Model X in the third quarter of 2015. We plan to deliver 80,000 to 90,000 new Model S and Model X vehicles in 2016.
    - shawn-furyan 10y ago
      So... we're about where we were at with the very first estimate... Precision isn't particularly helpful for this sort of rough projection. Which highlights that your original criticism wasn't particularly productive. clarification: In claiming that we're about where we started, I'm saying that a 10-20% correction doesn't significantly impact a rough order of magnitude estimation. The estimate was in the precision bounds of its stated goal. Therefore the estimate wasn't "ridiculous" at all, or at least, you haven't shown that it was.
      - honkhonkpants 10y ago
        That's not why I thought it was ridiculous. I said it was ridiculous for using projected 2016 Tesla production and dividing that by actual 2013 battery production, when battery production is rapidly expanding. You either have to use 2016 projected battery production on the denominator, or actual 2013 Tesla production (a number very close to zero) on the numerator.
        shawn-furyan 10y ago
        You've been criticizing the rough order of magnitude estimate for an hour and still haven't offered a significant improvement. I find that more more ridiculous. If the improvement is so obvious that not including it is ridiculous, then why not just produce the improvement you're talking about? Note: This is rough, back of the envelope projection meant to improve on a 5% figure that someone pulled out of the air.
        honkhonkpants 10y ago
        I think you're confused. _I_ am the one who said 5% and I think it's a reasonable working number. mikeash then replied, saying that Tesla will consume 22GWh (2018) and the battery market is only 35GWh/year (2013), implying that Tesla's share is so large it violates normal rules of market liquidity. Then I objected to that implication.

honkhonkpants 10y ago

OK, but in 2016 we don't have to guess how many cars Tesla built in 2015. It's historical fact.

shawn-furyan 10y ago
What is it? You could actually improve the estimate rather than /just/ pointing out that it has flaws. And your original criticism was vague. At least this one moves things forward. After a quick Google search, the number of vehicles Tesla sold in 2015 does in fact seem to be a bit uncertain. It seems they sold over 50,000 vehicles, but I've not found a more precise number, in a few minutes of looking. Sales from previous years seem to be: 2012 - 2,650 2013 - 22,477 2014 - 31,655 2015- ~50,000 though I got these numbers from a quora post, so take them with an adequately large dose of salt. edit: added google findings, tweaked wording to be more specific
- honkhonkpants 10y ago
  There is no reason to guess at these numbers OR to Google for other people's guesses. The sales figures to 5 significant digits are in Tesla's 10-K report. For example: During 2015, we achieved significant efficiencies in Model S production and produced 14,037 vehicles in the fourth quarter of 2015. We began production of Model X in the third quarter of 2015. We plan to deliver 80,000 to 90,000 new Model S and Model X vehicles in 2016.
  - shawn-furyan 10y ago
    So... we're about where we were at with the very first estimate... Precision isn't particularly helpful for this sort of rough projection. Which highlights that your original criticism wasn't particularly productive. clarification: In claiming that we're about where we started, I'm saying that a 10-20% correction doesn't significantly impact a rough order of magnitude estimation. The estimate was in the precision bounds of its stated goal. Therefore the estimate wasn't "ridiculous" at all, or at least, you haven't shown that it was.
    - honkhonkpants 10y ago
      That's not why I thought it was ridiculous. I said it was ridiculous for using projected 2016 Tesla production and dividing that by actual 2013 battery production, when battery production is rapidly expanding. You either have to use 2016 projected battery production on the denominator, or actual 2013 Tesla production (a number very close to zero) on the numerator.
      - shawn-furyan 10y ago
        You've been criticizing the rough order of magnitude estimate for an hour and still haven't offered a significant improvement. I find that more more ridiculous. If the improvement is so obvious that not including it is ridiculous, then why not just produce the improvement you're talking about? Note: This is rough, back of the envelope projection meant to improve on a 5% figure that someone pulled out of the air.
        honkhonkpants 10y ago
        I think you're confused. _I_ am the one who said 5% and I think it's a reasonable working number. mikeash then replied, saying that Tesla will consume 22GWh (2018) and the battery market is only 35GWh/year (2013), implying that Tesla's share is so large it violates normal rules of market liquidity. Then I objected to that implication.