Editing Efficiency ratio (section)

==Formula== 
: Efficiency = {{big|{{sfrac|input | output}}}} <ref>{{citation |url=https://www.accountingtools.com/articles/what-is-the-formula-for-calculating-efficiency.html |title=Accounting Tools|date=7 December 2023 }}</ref>

If expenses are {{US$|long=no|60}} and revenue is {{US$|long=no|80}} (perhaps net of interest revenue/expense) the efficiency ratio is 0.75 or 75% (60/80) – meaning that {{US$|long=no|0.75}} are spent for every dollar earned in revenue.

===An example===
Citigroup, Inc. (2003):
*Revenues, net of interest expense: 77,442<ref>{{citation |url=https://www.sec.gov/Archives/edgar/data/831001/000104746904006087/a2129612z10-k.htm |title=Citigroup 10K}}</ref>
*Operating expenses: 39,168<ref>{{citation |url=https://www.sec.gov/Archives/edgar/data/831001/000104746904006087/a2129612z10-k.htm |title=Citigroup 10K}}</ref>

That makes the efficiency ratio = {{sfrac|39,168|77,442}} = 0.51 or 51%.

If "benefits, claims, and credit losses", for 11,941, are added to operating expenses, the efficiency ratio worsens to {{sfrac|51,109|77,442}} = 0.66 
<!-- This really makes no sense: it inverts numerator and denominator in the definition! And it is impossible to make sense of the numbers. Can anybody fix it, please 
===Alternative===
If it's calculated as revenue divided by expenses (interest expense, "benefits, claims, and credit losses", operating expenses) it becomes 1 minus the "income from continuing operations" margin.
 68,380 / 94,713 = 0.72
-->