Here is a trap that is easy to fall in to. Confusing correlation as causation. As analysts, it is our job to see the data as it is rather than imply causation that doesn’t exist.
Let’s sample a chart, recently featured in Economist’s graphic detail under the title Measuring well-being.
At the end of the article they show the above chart and say, (emphasis mine)
BCG also compared financial inclusion (the percentage of individuals aged 15 or over with a bank account) against each country’s SEDA score, revealing a clear relationship.The report’s authors found that countries with higher financial inclusion generally had higher well-being than their peers at a similar income level.
Now, it is easy to misunderstand above chart and come to a conclusion that if you provide bank accounts to everyone in a country, then the country’s SEDA score (well-being) would improve.
But this would be wrong.
As an analyst leaning towards awesomeness, you want to ask questions like,
- Is it a coincidence that countries with higher well-being naturally have bank accounts for everyone?
- How does having a bank account impact a person’s well being?
- What other factors can contribute to well being? What about access to education, healthcare and information?
So there you go. Next time you see data or visual analysis that exhibits correlations, do not confuse them as causation. Question the factors first.
More charting principles and guidelines for you
- How to select right chart for your data
- Don’t make your charts heavier than they should be
- Avoid data dumps in your charts
- Understand data to ink ratio to make better charts
Do you often confuse correlation with causation?
Have you seen such misinterpretation of data in your work life? What was it like? Please share your thoughts in the comments section.
15 Responses to “Christmas Gift List – Set your budget and track gifts using Excel”
[...] Christmas Gift List – Set your budget and track gifts using Excel … [...]
I'm confused: if you spend $10, and your budget is $40, shouldn't the amount in the "Within Budget?" column stay black, since you didn't go over budget?
In other words, since we overspent on the electronic photo frame, shouldn't the $8 cell turn red?
@JP.. maybe Steven is encouraging consumerism... ?
I havent realized it earlier, but now I see it. If you unprotect the sheet, you can change the formula in Column I to =IF(G13=0;" ";F13-G13) from =IF(G13=0;" ";G13-F13), that should correct the behavior.
Thanks Chandoo. I thought of making a shopping list spreadsheet for Christmas, but this is neat so I think I'll use this instead.
Chandoo & Steven thanks for this spreadsheet. But for the sake of a person who has been staring at this megaformula in vain for the last 40 mins and not afraid to ask, would it be possible for you to walk us through the logic used here?
=SUM(SUMPRODUCT(SUBTOTAL(3,OFFSET($K$13:$K$62,ROW($K$13:$K$62)-MIN(ROW($K$13:$K$62)),0,1)),--($K$13:$K$62="-"))+SUMPRODUCT(SUBTOTAL(3,OFFSET($K$13:$K$62,ROW($K$13:$K$62)-MIN(ROW($K$13:$K$62)),0,1)),--($K$13:$K$62="0")))&" / "&SUBTOTAL(2,$G$13:$G$62)
Thanks Chandoo.. This is one of the best budget spreadsheets I've ever seen.. The Arrays are out of this world!! And it's FREE!!
Chandoo, can you tell us more about Steven? Does he have his own site?
JP, I think Chandoo changed it when he changed the currency formatting from £ to $, a negative figure is a good thing in this case. But don't change the formulas, the overbudget and under budget won't work properly if you do. Also Chandoo I think you've accidentally broke the conditional formatting for the alternating row colouring the formula is different to the version I sent you. As for the megaformula chrisham, it gave me a headache trying to get it all working, so I will let Chandoo talk you through it.
Hi,
In cells I6 and I7, I understand that subtotal together with offset function returns an array of ones after which, the sumproduct function gives the desired result.
But I’m not able to figure out the reason for using an array in I8 to return the most expensive gift.
Can’t the formula be just
“=VLOOKUP(SUBTOTAL(4,$G$13:$G$62),$G$13:$J$62,4,0)”
Savithri, Cell I8 needs the array, if the formula was “=VLOOKUP(SUBTOTAL(4,$G$13:$G$62),$G$13:$J$62,4,0)” it would find the highest price from the filtered range (i.e. highest actual in filtered range is $50) BUT then return the first person with that actual, not looking in just the filtered range (so first person on the list with a $50 actual.)
To see what I mean, change the formula, then change all the actuals to $50 then filter for baby, it lists the first name on the list.
But a good question 🙂
Thank you. I now realise that the array is used to get the ‘filtered range’ instead of the entire range, as table array for look up value.
[...] Download This Template [...]
this looks like an awesome excel sheet!! is there anyway i can get it emailed to me unprotected? for some reason, i am unable to download it 🙁 help!!
Hi I also can not download to a mac as the sheet is protected any help would be great
[...] to send her a pricey present. Rather, send a card with a picture of your child. Here’s a cool Excel sheet that will help you estimate your budget per person and let you track [...]
[...] husband and I pour/poor over the Christmas spreadsheet (yes, I do know how dorky that sounds, but we’re not the only ones!), figuring out who should give what to whom. We live at a distance from most of our family, so it [...]