By Gregory Piatetsky, KDnuggets.

Money can't buy votes, apparently.

Candidate Iowa 2016

Votes Total Ads

($MM) $Spend

/Vote SuperPac % Ted Cruz 51666 7.43 143.8 61% Donald Trump 45427 3.564 78.5 1% Marco Rubio 43165 11.73 271.7 61% Ben Carson 17395 3.609 207.5 9% Rand Paul 8481 1.316 155.2 93% Jeb Bush 5238 14.051 2682.5 100% Carly Fiorina 3485 0.831 238.5 57% John Kasich 3474 0 na 0% Mike Huckabee 3345 2.76 825.1 100% Chris Christie 3284 0.587 178.7 93% Rick Santorum 1783 0.032 17.9 91%

The Iowa caucuses, held on Feb 1, 2016, attracted a lot of attention and a lot of advertising money.An interesting quantitative angle on the Republican side was the story Jeb Bush Spent $2,800 Per Vote In Iowa , which showed a chart of money spent per vote and suggestedHowever, a one-dimensional chart like this cannot be used to make any inferences about relationship of money and votes, so I decided to investigate.I got the ad spending money from Morning Consult and charted the votes vs ad spend.Here the size of the circle corresponds to total ad spend / vote, and the color to % of money from SuperPacs (red - 100%, green - zero). Only Trump and Carson had most of their ad money from their campaign (green circles), while other candidate ads were mostly paid for by SuperPacs.The chart shows that Jeb Bush result is an anomaly, with about $2,700 / vote (slightly different, but close to $2,800 reported in Huffington Post).Including Jeb, the regression forhas R=0.21 - almost no correlation.However, if we remove Jeb, the picture changes, with R=0.67, a strong correlation, and, on average, one vote cost $210 of ad spend.We also note that Trump ($78/vote) and Cruz ($144/vote) got the best "deal", while Huckabee has the second worst "deal" (after Jeb Bush) with $825/vote.We also note that Rubio result is less of a surprise, considering his huge ad spend.Another interesting angle is days in Iowa vs votes.The political tradition says that candidates need to spend a lot of time in Iowa to succeed.Looking at all the candidates, there is actually a negative relationship, since 3 of the lowest performing candidates - Santorum, Huckabee, and Fiorina, spent the most time in Iowa.Circle size corresponds to total ad spend by the candidate.What do you think? Comment below.Here is the data.