Poll Analysis: Playing with questionable polls

Clinton	Trump
84.5% probability of winning	15.5% probability of winning
Mean of 282 electoral votes	Mean of 256 electoral votes

Yesterday’s analysis showed Sec. Hillary Clinton (D) leading Donald Trump (R) with 290 EVs to 248 EVs. If the election was held yesterday, we would expect Clinton to win with an 86.8% chance.

Since that analysis there have been about 28 new polls release that satisfy my inclusion criteria. I should point out, that the new polls include eight new polls from Remington Research (R) and four from Trafalgar Group (R). If the significance of this escapes you, read Goldy’s post.

One of the things I am going to do in this analysis is do two analyses: one with these two pollsters included, and one that excludes all Remington and Trafalgar polls. Pick the one you wish.

Which one is right? It is hard to say. I hate accusing a pollster of producing bogus polls. I’ve had numerous people complain about including this poll or that poll, and I ignore them. The entire premise of my effort is that by aggregating polls broadly, any “house effects” will cancel. But the oddities of Remington are clear. Trafalgar polls also seem quite dodgy.

Okay…Here we go. Scroll down or click here for the alternative analysis.

Analysis with All Polls

Today, after 100,000 simulated elections, Clinton wins 84,508 times and Trump wins 15,492 times (including the 2,449 ties). Clinton received (on average) 282 (-8) to Trump’s 256 (+8) electoral votes. In an election held now, Clinton would have a 84.5% probability of winning and Trump would have a 15.5% probability of winning. Thus, Clinton slips a bit, but the race isn’t changing much.

The long term trends in this race can be seen from a series of elections simulated every seven days using polls from 07 Nov 2015 to 07 Nov 2016, and including polls from the preceding ten days (FAQ).

An animated sequence of maps and electoral vote distributions can be seen here

Here is the distribution of electoral votes [FAQ] from the simulations:

Ten most probable electoral vote outcomes for Clinton (full distribution here):

• 276 electoral votes with a 9.03% probability
• 275 electoral votes with a 7.47% probability
• 272 electoral votes with a 4.95% probability
• 273 electoral votes with a 4.92% probability
• 274 electoral votes with a 4.75% probability
• 271 electoral votes with a 3.59% probability
• 305 electoral votes with a 3.09% probability
• 304 electoral votes with a 2.55% probability
• 269 electoral votes with a 2.45% probability
• 302 electoral votes with a 2.45% probability

After 100,000 simulations:

• Clinton wins 84.5%, Trump wins 15.5%.
• Average (SE) EC votes for Clinton: 282.3 (16.1)
• Average (SE) EC votes for Trump: 255.7 (16.1)
• Median (95% CI) EC votes for Clinton: 276 (255, 318)
• Median (95% CI) EC votes for Trump: 262 (220, 283)

Each column of this table shows the electoral vote total aggregated by different criteria for the probability of winning a state (Safe=100%, Strong=90%+, Leans=60%+, Weak=50%+):

Threshold	Safe	+ Strong	+ Leans	+ Weak
Safe Clinton	119
Strong Clinton	139	258
Leans Clinton	18	18	276
Weak Clinton	0	0	0	276
Weak Trump	0	0	0	262
Leans Trump	36	36	262
Strong Trump	101	226
Safe Trump	125

This table summarizes results by state. Click on the poll count to see the individual polls included for the state.

	1	0	EC	#	Total	%	%	Clinton	Trump
	2	8	Votes	polls	Votes	Clinton	Trump	% wins	% wins
AL			9	1*	2400	40.0	60.0	0.0	100.0
AK			3	1*	360	52.2	47.8	73.1	26.9
AZ			11	6	3965	47.4	52.6	1.0	99.0
AR			6	1*	556	37.9	62.1	0.0	100.0
CA			55	1	675	61.6	38.4	100.0	0.0
CO			9	7	11120	52.4	47.6	100.0	0.0
CT			7	1*	847	58.8	41.2	100.0	0.0
DE			3	1*	618	62.9	37.1	100.0	0.0
DC			3	1*	1131	76.5	23.5	100.0	0.0
FL			29	10	10074	49.6	50.4	27.1	72.9
GA			16	6	5392	47.8	52.2	1.0	99.0
HI			4	1*	801	61.9	38.1	100.0	0.0
ID			4	1*	774	30.9	69.1	0.0	100.0
IL			20	1	470	56.4	43.6	97.5	2.5
IN			11	2	868	43.7	56.3	0.4	99.6
IA			6	3	1715	47.9	52.1	10.9	89.1
KS			6	2	826	41.2	58.8	0.0	100.0
KY			8	2*	1267	38.4	61.6	0.0	100.0
LA			8	4*	2145	42.1	57.9	0.0	100.0
ME			2	1	660	52.3	47.7	78.6	21.4
ME1			1	1	345	53.3	46.7	80.1	19.9
ME2			1	1	323	51.1	48.9	62.6	37.4
MD			10	2*	1062	70.0	30.0	100.0	0.0
MA			11	1	342	68.4	31.6	100.0	0.0
MI			16	8	5958	51.5	48.5	94.2	5.8
MN			10	2*	1111	55.3	44.7	99.5	0.5
MS			6	1*	987	42.9	57.1	0.2	99.8
MO			10	6	4533	43.2	56.8	0.0	100.0
MT			3	2*	1345	46.1	53.9	1.6	98.4
NE			2	1*	594	34.5	65.5	0.0	100.0
NE1			1	1*	191	35.6	64.4	0.3	99.7
NE2			1	1*	207	44.9	55.1	14.6	85.4
NE3			1	1*	199	23.6	76.4	0.0	100.0
NV			6	6	5417	48.6	51.4	6.9	93.1
NH			4	8	4865	50.9	49.1	80.4	19.6
NJ			14	1	617	56.1	43.9	98.2	1.8
NM			5	3	9005	51.3	48.7	95.3	4.7
NY			29	1	525	60.0	40.0	100.0	0.0
NC			15	7	7304	48.8	51.2	8.2	91.8
ND			3	1*	300	42.7	57.3	3.3	96.7
OH			18	5	5722	48.5	51.5	6.7	93.3
OK			7	1*	477	33.3	66.7	0.0	100.0
OR			7	1*	378	54.8	45.2	89.9	10.1
PA			20	12	12143	51.3	48.7	98.3	1.7
RI			4	1*	504	61.9	38.1	100.0	0.0
SC			9	2*	1509	42.9	57.1	0.0	100.0
SD			3	3*	1857	43.5	56.5	0.0	100.0
TN			11	2*	1185	43.0	57.0	0.1	99.9
TX			38	3	2489	43.7	56.3	0.0	100.0
UT			6	4	1912	40.8	59.2	0.0	100.0
VT			3	1*	437	69.1	30.9	100.0	0.0
VA			13	8	8438	52.0	48.0	99.7	0.3
WA			12	1	598	57.0	43.0	99.3	0.7
WV			5	1*	440	31.8	68.2	0.0	100.0
WI			10	5	6637	53.4	46.6	100.0	0.0
WY			3	1*	563	25.6	74.4	0.0	100.0

^* An older poll was used (i.e. no recent polls exist).

Analysis without Remington and Trafalgar

Scroll up or click here for the standard analysis.

This analysis excludes all Remington and Trafalgar polls.

Clinton	Trump
98.7% probability of winning	1.3% probability of winning
Mean of 310 electoral votes	Mean of 228 electoral votes

Now, after 100,000 simulated elections, Clinton wins 98,707 times and Trump wins 1,293 times (including the 231 ties). Clinton received (on average) 310 to Trump’s 228 electoral votes. In an election held now, Clinton would have a 98.7% probability of winning and Trump would have a 1.3% probability of winning.

This is quite a stark difference. If Remington and Trafalgar are trying to fuck with the poll aggregators, they have likely succeeded!

Here is the distribution of electoral votes [FAQ] from the simulations:

Ten most probable electoral vote outcomes for Clinton (full distribution here):

• 305 electoral votes with a 5.09% probability
• 320 electoral votes with a 4.35% probability
• 304 electoral votes with a 3.99% probability
• 319 electoral votes with a 3.44% probability
• 311 electoral votes with a 2.93% probability
• 302 electoral votes with a 2.79% probability
• 317 electoral votes with a 2.76% probability
• 301 electoral votes with a 2.69% probability
• 303 electoral votes with a 2.54% probability
• 310 electoral votes with a 2.49% probability

After 100,000 simulations:

• Clinton wins 98.7%, Trump wins 1.3%.
• Average (SE) EC votes for Clinton: 309.9 (16.2)
• Average (SE) EC votes for Trump: 228.1 (16.2)
• Median (95% CI) EC votes for Clinton: 310 (274, 339)
• Median (95% CI) EC votes for Trump: 228 (199, 264)

Each column of this table shows the electoral vote total aggregated by different criteria for the probability of winning a state (Safe=100%, Strong=90%+, Leans=60%+, Weak=50%+):

Threshold	Safe	+ Strong	+ Leans	+ Weak
Safe Clinton	109
Strong Clinton	156	265
Leans Clinton	40	40	305
Weak Clinton	0	0	0	305
Weak Trump	15	15	15	233
Leans Trump	40	40	218
Strong Trump	60	178
Safe Trump	118

This table summarizes results by state. Click on the poll count to see the individual polls included for the state.

	1	0	EC	#	Total	%	%	Clinton	Trump
	2	8	Votes	polls	Votes	Clinton	Trump	% wins	% wins
AL			9	1*	2400	40.0	60.0	0.0	100.0
AK			3	1*	360	52.2	47.8	72.4	27.6
AZ			11	6	3965	47.4	52.6	1.0	99.0
AR			6	1*	556	37.9	62.1	0.0	100.0
CA			55	1	675	61.6	38.4	100.0	0.0
CO			9	4	7703	53.2	46.8	100.0	0.0
CT			7	1*	847	58.8	41.2	100.0	0.0
DE			3	1*	618	62.9	37.1	100.0	0.0
DC			3	1*	1131	76.5	23.5	100.0	0.0
FL			29	6	4848	51.2	48.8	87.8	12.2
GA			16	5	4180	48.2	51.8	5.0	95.0
HI			4	1*	801	61.9	38.1	100.0	0.0
ID			4	1*	774	30.9	69.1	0.0	100.0
IL			20	1	470	56.4	43.6	97.1	2.9
IN			11	2	868	43.7	56.3	0.3	99.7
IA			6	3	1715	47.9	52.1	11.1	88.9
KS			6	2	826	41.2	58.8	0.0	100.0
KY			8	2*	1267	38.4	61.6	0.0	100.0
LA			8	4*	2145	42.1	57.9	0.0	100.0
ME			2	1	660	52.3	47.7	80.0	20.0
ME1			1	1	345	53.3	46.7	81.6	18.4
ME2			1	1	323	51.1	48.9	61.7	38.3
MD			10	2*	1062	70.0	30.0	100.0	0.0
MA			11	1	342	68.4	31.6	100.0	0.0
MI			16	7	4806	52.1	47.9	97.7	2.3
MN			10	2*	1111	55.3	44.7	99.3	0.7
MS			6	1*	987	42.9	57.1	0.1	99.9
MO			10	5	2983	43.1	56.9	0.0	100.0
MT			3	2*	1345	46.1	53.9	2.0	97.9
NE			2	1*	594	34.5	65.5	0.0	100.0
NE1			1	1*	191	35.6	64.4	0.2	99.8
NE2			1	1*	207	44.9	55.1	15.2	84.8
NE3			1	1*	199	23.6	76.4	0.0	100.0
NV			6	3	2020	48.7	51.3	20.2	79.8
NH			4	8	4865	50.9	49.1	79.1	20.9
NJ			14	1	617	56.1	43.9	98.4	1.6
NM			5	3	9005	51.3	48.7	96.0	4.0
NY			29	1	525	60.0	40.0	99.9	0.1
NC			15	4	2735	49.7	50.3	42.1	57.9
ND			3	1*	300	42.7	57.3	4.4	95.6
OH			18	3	2366	48.3	51.7	12.4	87.6
OK			7	1*	477	33.3	66.7	0.0	100.0
OR			7	1*	378	54.8	45.2	90.4	9.6
PA			20	9	7368	51.9	48.1	98.9	1.1
RI			4	1*	504	61.9	38.1	100.0	0.0
SC			9	1*	380	47.4	52.6	22.7	77.3
SD			3	2*	909	43.5	56.5	0.1	99.9
TN			11	2*	1185	43.0	57.0	0.0	100.0
TX			38	3	2489	43.7	56.3	0.0	100.0
UT			6	3	974	39.2	60.8	0.0	100.0
VT			3	1*	437	69.1	30.9	100.0	0.0
VA			13	6	4663	52.3	47.7	98.8	1.2
WA			12	1	598	57.0	43.0	99.3	0.7
WV			5	1*	440	31.8	68.2	0.0	100.0
WI			10	3	2630	53.0	47.0	98.6	1.4
WY			3	1*	563	25.6	74.4	0.0	100.0

^* An older poll was used (i.e. no recent polls exist).

Details of the methods are given in the FAQ.

The most recent analysis in this match-up can be found from this page.