2008 Election Model

A Monte Carlo Electoral Vote Simulation

Updated: Nov. 3, 2008

TruthIsAll

FINAL PROJECTION:

Obama wins by 76-64m votes; 367-171 EV (median); 365.3 expected; 53-45% vote share

The Election Model (EM) assumes as a base case that a fraud-free election is held today – and that current polls reflect the true vote. The model projects that Obama will win the Electoral vote by 367-171 and the True Vote by 76-64m. The final projected vote share is Obama 53.1- McCain 44.9%- Other 2.0%. The state poll aggregate vote share matched the national average tracking poll to within 0.2%.

The model projects that Obama will carry 30 states + DC:

CA CO CT DE FL HI IL IA ME MD / MA MI MN MO MT NV NH NJ NM NY / NC ND OH OR PA RI VT VA WA WI

In May, the 2008 Election Calculator (EC) projected that Obama would win the True Vote by 71-59m (54.1-44.7%).

For the 2008 EC to match the EM, its estimate of returning 60.5m returning Kerry and 51.6m Bush voters had to be accurate.

The EC used 12:22am 2004 NEP vote shares to calculate the projections.

In other words, the 2008 EC and EM confirmed that Kerry won a landslide (see below).

These graphs display the trend from May 29-Nov. 3: Electoral vote and projected vote share trend and State vs. National vote share projection trend.

The average of recent state polls is entered in the database. The EM assumes that 60% of the undecided voters will break to Obama (base case). The undecided vote allocation (UVA) is based on the assumption that Obama is the challenger and McCain is running for Bush’s third term (GWB is not the most popular of incumbents). The EM base case allocates a conservative 60% of the undecided vote to Obama; most pollsters typically use 70-90%, depending on the incumbent’s approval rating. Bush is at 22% and McCain 45%.

The model projects five vote share scenarios of undecided voter allocations (UVA) ranging from 40-90%. Obama won the base case scenario with an average 365.8 EV. The median and mode were 367. Even in the worst-case 40% UVA scenario Obama won all 5000 election trials.

The Monte Carlo mean EV (365.8) matched the theoretical expected EV (365.3), illustrating the Law of Large Numbers (LLN): 5000 simulated election trials were required for the MEAN EV to CONVERGE to the THEORETICAL EV (the simulation is in the “long run”). It is computational overkill to perform a meta analysis requiring the calculation of millions of EV combination scenarios in order to calculate the win probabilities.

Obama exceeded 360 EV in 3333 of 5000 Monte Carlo election trial simulations, so he has a 66.7% probability of winning at least 360 EV. The Monte Carlo simulation is displayed in this Electoral Vote Simulation Frequency chart. Note that ALL 5000 election trials are to the right of the 270 mark; therefore Obama’s win probability is 100%.

		2008 Election Model
		Final Monte Carlo Simulation
		TruthIsAll
		Updated:	11/3/08	10:13 AM
Assumptions:
143.0	Votes cast	138.7	Recorded	(in millions)
3.0%	Uncounted	4.3	75%	to Obama
2.0%	3rd party	2.9	Nader, Barr, McKinney et al
60%	Undecided Voters (UVA) allocated to Obama
National Model			Obama	McCain	Other	Margin
Tracking Poll Avg (%)			51.1	43.9	5.0	7.3
Projected True Vote %			52.9	45.1	2.0	7.9
Projected True Vote (mil)			75.7	64.4	2.9	11.3
Proj. Recorded Vote %			52.3	45.7	2.1	6.6	(True Vote less Uncounted)
Proj. Recorded Vote (mil)			72.5	63.4	2.9	9.1
Proj. 2-party True Vote %			54.1	45.9	0.0	8.3
State Model
Aggregate Poll Avg (%)			51.3	43.8	4.9	7.6
Projected True Vote %			53.1	44.9	2.0	8.2
Projected True Vote (mil)			75.9	64.2	2.9	11.7
Proj. Recorded Vote %			52.4	45.5	2.1	6.9	(True Vote less Uncounted)
Proj. Recorded Vote (mil)			72.7	63.2	2.9	9.5
Proj. 2-party True Vote %			54.3	45.7	0.0	8.6
Electoral Vote Snapshot
Poll Leader			367	171	Before UVA
Projected Leader			370	168	After UVA
Expected EV			365.29	172.71	EV = ∑ (Win probability (i) * EV(i)), i=1,51 states
Monte Carlo Electoral Vote Simulation (5000 election trials)
Mean			365.81	172.19	Average
Median			367	171	Middle value
Mode			367	171	Most likely
Maximum			414	124
Minimum			294	244
Obama Electoral Vote Win Probabilities
Electoral Vote			320	330	340	350	360	370	380	390	400	410	420
Trial Wins > EV			4969	4832	4668	4218	3333	2270	1072	380	50	3	0
Change in Trial Wins			31	137	164	450	885	1063	1198	692	330	47	3
Prob. Trial Wins > EV			99.38%	96.64%	93.4%	84.4%	66.7%	45.4%	21.4%	7.6%	1.00%	0.06%	0.00%

			STATE POLL MODEL				NATIONAL POLL MODEL			ELECTORAL VOTE
		Wtd Avg	2-Party	2-Party	Actual	Moving	2-Party	2-Party	Actual	Expected
		Polls	Current	Proj	Proj	Average	Current	Proj	Proj	Value
	11/3/08			60% UVA				60% UVA
	Obama	51.3	54.0	54.28	53.08	51.1	53.8	54.14	52.94	365.3
	McCain	43.8	46.0	45.7	44.9	43.9	46.2	45.9	45.1	172.7
	map
	11/01/04			75% UVA				75% UVA
	Kerry	47.9	50.5	51.8	51.1	47.8	50.6	51.8	51.3	337
	Bush	46.9	49.5	48.2	47.9	46.6	49.4	48.2	47.8	201
	map
	Impact of Uncounted and Switched Votes on Obama 2-party Aggregate Vote Share and Expected EV
	Uncounted		1%			2%			3%
	Switched		Vote	EV		Vote	EV		Vote	EV
	4.0%		52.0	311		51.8	305		51.6	319
	8.0%		49.8	276		49.6	272		49.4	266
	10.0%		48.7	251		48.5	247		48.3	242
	Impact of Undecided Voter Allocation (UVA) on Obama 2-party Aggegate Vote Share and Expected EV
				Current		Base case
	UVA	40%		54.0%		60%		75%		90%
	Projected 2-Party Vote Share
	Obama	53.3		54.0		54.3		55.0		55.7
	McCain	46.7		46.0		45.7		45.0		44.3
	MoE	Obama Popular Vote Win Probability (Normdist)
	1.0%	100.0		100.0		100.0		100.0		100.0
	2.0%	99.9		100.0		100.0		100.0		100.0
	3.0%	98.4		99.5		99.7		99.9		100.0
	Obama Electoral Vote: Monte Carlo Simulation (5000 election trials)
	Mean	345.0		359.0		365.8		379.5		393.8
	Median	347		362		367		381		396
	Mode	367		367		367		381		396
	Maximum	395		406		414		421		445
	Minimum	289		294		294		317		333
	Electoral Vote Win Probability
	Trial Wins	5000		5000		5000		5000		5000
	Probability	100.0		100.0		100.0		100.0		100.0
	95% EV Confidence Interval
	Upper	381		394		399		409		421
	Lower	309		324		333		350		367
	States Won
	Obama	28		30		31		32		33
			Sensitivity Analysis II - Projected 2-party vote share and win probability
			Vote share	48.0	49.0	50.0	51.0	52.0	53.0
			MoE			Popular Vote Win Probability
			1.0%	0.0	2.5	50.0	97.5	100.0	100.0
			2.0%	2.5	16.4	50.0	83.6	97.5	99.8
			3.0%	9.6	25.7	50.0	74.3	90.4	97.5
POLLING ANALYSIS AND PROJECTIONS
National Model
http://www.realclearpolitics.com/epolls/2008/president/us/general_election_mccain_vs_obama-225.html
0.47	State aggregate vs. National vote share correlation
					Current Poll Average				7-Poll Moving Average				Projected Moving Average Vote (60% UVA)
	Poll	Date	Sample	MoE	Obama	McCain	Other	Spread	Obama	McCain	Spread	WinPr	Obama	McCain	Spread	WinPr
	Research2k	11/02	1100LV	2.95%	51	44	5	7	51.1	43.9	7.3	100.0	54.1	45.9	8.3	100.0
	Gallup	11/02	2847RV	1.84%	52	41	7	11	51.1	43.7	7.4	100.0	54.2	45.8	8.5	100.0
	Zogby	11/02	1201LV	2.83%	51	44	5	7	51.0	44.0	7.0	100.0	54.0	46.0	8.0	100.0
	Hotline/FD	11/02	882LV	3.30%	50	45	5	5	50.7	43.7	7.0	99.8	54.1	45.9	8.1	100.0
	Rasmussen	11/02	3000LV	1.79%	51	46	3	5	51.3	43.1	8.1	99.2	54.6	45.4	9.3	99.7
	ABC/WP	11/02	2446RV	1.98%	54	42	4	12	51.1	42.7	8.4	100.0	54.8	45.2	9.7	100.0
	Battleground	10/30	1000LV	3.10%	49	45	6	4	50.1	43.0	7.1	96.6	54.3	45.7	8.5	99.1
	NBC/WSJ	11/02	1011LV	3.08%	51	43	6	8	50.3	43.0	7.3	100.0	54.3	45.7	8.6	100.0
	CNN	11/01	1017LV	3.07%	51	43	6	8	50.4	42.0	8.4	99.9	55.0	45.0	9.9	100.0
	Pew	11/01	2587RV	1.93%	49	42	9	7	50.7	41.7	9.0	100.0	55.3	44.7	10.5	100.0
	CBS	10/31	1005LV	3.09%	54	41	5	13	51.1	41.3	9.9	99.9	55.7	44.3	11.4	100.0
	Marist	10/29	543LV	4.21%	50	43	7	7	50.4	41.1	9.3	92.6	55.5	44.5	11.0	99.0
	FOX News	10/29	924LV	3.22%	47	44	9	3	50.9	40.6	10.3	98.6	56.0	44.0	12.0	99.6
	Ipsos	10/27	831LV	3.40%	50	45	5	5	51.3	40.3	11.0	100.0	56.3	43.7	12.7	100.0
	Pew	10/26	1325RV	2.69%	52	36	12	16	51.6	39.9	11.7	100.0	56.7	43.3	13.4	100.0
				LV	50.45	43.91	5.64	6.55
				RV	51.75	40.25	8.00	11.50
				Total	50.80	42.93	6.27	7.87
				2-party	54.20	45.80	0.00	8.39
State Model
http://www.electoral-vote.com/
http://www.realclearpolitics.com/epolls/maps/obama_vs_mccain/#data
Poll MoE	3.0%		LATEST STATE POLLS							2004 PROJECTIONS, EXIT POLLS, ACTUALS
										Kerry			Recorded Vote		Obama vs
						Obama	Obama	KEY STATES		Proj.	Unadj.	Recd	Deviation from		Kerry	Flip (*)
			Obama	McCain	Spread	2pty Proj.	WinProb	(within MoE)		Vote	EP	Vote	Proj.	Exit	2pty Proj.	States
	Last Poll	Popular	51.34	43.77	7.57	54.28	100.0	Allocation		51.02	51.98	48.27	2.75	3.71	2.76	12
	Date	Electoral	367	171	196	370	365.3	Percent	Rank	337	337	252	85	85	33	128
AL	10/28	9	36	61	(25)	37.8	0.0			41.3	41.8	36.8	4.4	5.0	(4.0)	AL
AK	10/30	3	40	58	(18)	41.2	0.0			39.0	40.2	35.5	3.5	4.7	1.7	AK
AZ	10/30	10	46	50	(4)	48.4	14.8	6.0	8	48.0	44.5	44.4	3.6	0.1	(0.1)	AZ
AR	10/31	6	44	51	(7)	47.0	2.5	1.4	12	49.8	45.2	44.5	5.2	0.6	(3.3)	AR
CA	10/31	55	60	36	24	62.4	100.0			55.0	60.1	54.3	0.7	5.8	6.9	CA
CO	10/30	9	51	45	6	53.4	98.7	3.2	9	50.0	50.1	47.0	3.0	3.1	2.9	CO*
CT	10/22	7	56	35	21	61.4	100.0			55.8	62.3	54.3	1.4	8.0	5.2	CT
DC	9/13	3	90	9	81	90.6	100.0			85.5	90.6	89.2	(3.7)	1.4	4.6	DC
DE	10/28	3	63	33	30	65.4	100.0			57.0	61.3	53.3	3.7	8.0	7.9	DE
FL	11/2	27	49	47	2	51.4	82.0	22.7	1	51.5	51.0	47.1	4.4	3.9	(0.6)	FL*
GA	10/30	15	46	49	(3)	49.0	25.7	10.8	3	45.8	42.0	41.4	4.4	0.6	2.8	GA
HI	9/20	4	68	27	41	71.0	100.0			51.8	58.1	54.0	(2.3)	4.1	18.8	HI
ID	9/17	4	33	62	(29)	36.0	0.0			37.5	32.3	30.3	7.2	2.0	(2.0)	ID
IL	11/1	21	60	37	23	61.8	100.0			56.3	56.6	54.8	1.4	1.8	5.1	IL
IN	11/2	11	46	48	(2)	49.6	39.7	9.2	5	40.5	40.4	39.3	1.2	1.1	8.6	IN
IA	11/1	7	54	39	15	58.2	100.0			53.8	50.7	49.2	4.5	1.5	4.0	IA*
KS	10/28	6	39	56	(17)	42.0	0.0			38.5	37.2	36.6	1.9	0.5	3.0	KS
KY	11/1	8	41	55	(14)	43.4	0.0			42.0	39.9	39.7	2.3	0.2	0.9	KY
LA	10/29	9	40	50	(10)	46.0	0.4			48.3	43.5	42.2	6.0	1.3	(2.8)	LA
ME	11/1	4	56	43	13	56.6	100.0			57.5	55.6	53.6	3.9	2.0	(1.4)	ME
MD	9/20	10	57	38	19	60.0	100.0			55.5	59.6	55.9	(0.4)	3.7	4.0	MD
MA	10/28	12	55	37	18	59.8	100.0			70.0	65.8	61.9	8.1	3.9	(10.7)	MA
MI	11/1	17	53	38	15	58.4	100.0			53.5	54.4	51.2	2.3	3.2	4.4	MI
MN	11/2	10	53	43	10	55.4	100.0			54.3	55.7	51.1	3.2	4.6	0.7	MN
MS	10/29	6	42	53	(11)	45.0	0.1			46.5	49.4	39.8	6.3	9.3	(2.0)	MS
MO	11/2	11	47	46	1	51.2	78.3	10.6	4	49.3	49.0	46.1	3.1	2.9	1.5	MO*
MT	11/2	3	48	47	1	51.0	74.3	2.9	10	40.5	37.3	38.6	1.9	(1.3)	10.0	MT*
NE	9/30	5	37	56	(19)	41.2	0.0			36.5	37.0	32.7	3.8	4.4	4.2	NE
NV	11/2	5	51	44	7	54.0	99.6	1.2	13	49.8	52.8	47.9	1.9	5.0	3.8	NV*
NH	10/30	4	53	42	11	56.0	100.0			50.8	57.2	50.2	0.5	7.0	4.8	NH
NJ	10/30	15	55	38	17	59.2	100.0			55.3	57.5	52.9	2.3	4.6	3.5	NJ
NM	10/31	5	53	45	8	54.2	99.7	0.6	14	49.8	53.0	49.0	0.7	4.0	4.0	NM*
NY	10/28	31	64	31	33	67.0	100.0			59.3	64.5	58.4	0.9	6.1	7.3	NY
NC	11/2	15	49	48	1	50.8	69.9	14.4	2	48.5	49.5	43.6	4.9	6.0	1.8	NC*
ND	10/29	3	46	47	(1)	50.2	55.2	2.9	10	41.8	34.6	35.5	6.3	(0.9)	8.0	ND*
OH	11/2	20	51	45	6	53.4	98.7	7.2	6	51.5	54.0	48.7	2.8	5.3	1.4	OH*
OK	10/29	7	34	63	(29)	35.8	0.0			35.5	33.8	34.4	1.1	(0.6)	(0.2)	OK
OR	10/30	7	56	39	17	59.0	100.0			53.8	53.0	51.3	2.4	1.7	4.8