This document summarizes a study that estimates the impact of early 20th century prohibition laws on mortality outcomes between 1900-1920. It makes three main improvements over previous studies: 1) uses a more accurate measure of state-level exposure to prohibition; 2) examines a wider range of mortality outcomes; and 3) analyzes differential effects in urban vs. rural areas. The study finds that increased exposure to early prohibition laws, as measured by the percentage of the population living in dry counties/states, significantly reduced alcoholism mortality and a summary index of alcohol-related disease mortality. It also finds a marginally significant reduction in accidents mortality and the poor decisions mortality index. These effects are larger than those found using prior studies' binary prohibition

1. Did Early Twentieth Century Alcohol
Prohibition Matter?
Mindy S. Marks
Northeastern University
Marc T. Law
University of Vermont
1

2. Our contributions
We estimate the impact of early prohibition (between 1900 to 1920) on a
wide range of mortality related outcomes.
We make three major improvements on existing literature
1. More accurate measure of state-level exposure to prohibition that (i)
corrects for timing of enforcement of statewide prohibition; and (ii)
accounts for the fact that dry counties were widespread prior to statewide
prohibition
Existing literature: prohibition as binary variable equal to 1 in year that
statewide prohibition is enacted.
All earlier years coded as 0 even though there were dry counties.
• Measurement error may have biased previous estimates toward zero.
2

3. Contributions…
2. Examine impact of prohibition exposure on a wider range of mortality outcomes
than previously investigated (including deaths due to alcoholism!)
Any mortality outcome that is plausibly related to alcohol consumption,
either through its impact on disease or on decision making. 12 in total
Existing literature: only looks at one or two outcomes at a time
Benefits
• More comprehensive picture
• Can aggregate mortality outcomes into 2 summary indices
• Summary indices will improve statistical power if effects go in same direction.
Solve the multiple hypothesis testing bias problem.
Reduce problems arising from miscoding of causes of death in early 20th
century 3

4. Contributions…
3. Gather within state data (i.e. area-level) on prohibition exposure and
selected alcohol related mortality outcomes for urban areas that were
wet prior to statewide or federal prohibition and non-urban areas that
were partially dry. Estimate the differential effect of statewide or federal
prohibition on mortality in urban areas vs. non-urban areas.
• Improves match between prohibition exposure and outcomes
• Different/New source of variation
• Can include state-by-year fixed effects
4

5. Prohibition history continued
Prohibition evolved gradually in US
Begins at local level, before going upward to state-level
# of dry counties in wet states: 62 in 1900; 772 in 1905; 1,030 in 1910
State-level prohibition follows (GA and OK in 1907; MS and NC in
1908; TN in 1909; WV in 1912; OR, WA, CO in 1914…)
Prohibition states tend to be:
1. rural
2. protestant
3. native born
4. white
5. where women can vote
5

6. Prohibition history continued
National prohibition takes effect in January 1920
• Passage of the 18th Amendment to US constitution and Volstead Act
Timing determined by key factors including:
• Battle for universal female suffrage at federal level (19th Amendment)
• Strength of Progressive movement
• Adoption of federal income tax (18th Amendment in 1913) reduces national
government’s reliance on alcohol tax revenue
{NB: alcohol taxes account for 1/3rd of federal gov’t revenue prior to 1913!}
See Okrent (2011) for great book on the political economy of the probation
movement
6

7. Data
Gathered data on the timing of state-level exposure to prohibition (both date
enacted and date effective)
Data on enacted is taken from Dills and Miron (2004), with updated
information from Evans, Helland, Klick and Patel (2015)
Information on date effective was taken from Pickett, Wilson, and
Smith (1917), National Association of Distillers and Wholesale Dealers
(1918) and online searches of historical society websites
Many states had 1-2 year gaps between date enacted and date effective
Prior studies: use date enacted instead of date effective
7

8. Date of adoption vs. date effective
8

9. Coding state-level prohibition exposure
For years before statewide prohibition:
• Exposure to prohibition equals the fraction of a state’s population that lives
in a dry county (merged ICPSR data on county-level prohibition collected
by Robert Sechrist with county level population counts from US censuses).
{In some states, more than half of the population lived in dry counties
before statewide prohibition}
For years after statewide prohibition takes effect:
• Exposure to prohibition equals 1.
During the year in which statewide prohibition takes effect
• Pro-rate by the fraction of the year in which it is in effect (to nearest month)
New treatment variable (Share_Dry) will fall in [0, 1] interval
9

10. Prohibition exposure in Colorado
10
Notes: Statewide_Dry_Enacted is the variable used by the literature
Statewide_Dry_Effective use date effective instead of date enacted
Share_Dry includes dry counties

11. Prohibition exposure in Ohio
11
Notes: Statewide_Dry_Enacted is the variable used by the literature
Statewide_Dry_Effective use date effective instead of date enacted
Share_Dry includes dry counties

12. Prohibition exposure in the registration area
12
Notes: Statewide_Dry_Enacted is the variable used by the literature
Statewide_Dry_Effective use date effective instead of date enacted
Share_Dry includes dry counties

13. Mortality data
Annual state-level mortality counts from 1900 to 1920 of all (mutually exclusive) reported
causes of death potentially related to alcohol according to medical and economics
literatures. Convert to rates (per 100,000 people).
Unit of observation: state-year (unbalanced panel)
Up to 35 registration states
States join in different years
Alcohol related diseases (8):
Alcoholism, Circulatory disease, Cirrhosis,
Infant mortality, Liver diseases, Peritonitis,
Stomach diseases, Ulcers
Poor decisions induced by excessive drinking (4):
Accidents*, Homicides, Suicides, Syphilis
* fractures, burns and scalds, heat and sunstroke, cold and freezing, lighting, drowning,
inhalation of poisonous gases, accidental poisonings, accidental gunshot wounds, injuries
by machinery, injuries in mines and quarries, railroad accidents, streetcar accidents, injuries
by vehicles and horses
13

14. Summary indices
Use cause-specific mortality rates to construct two summary indices
1. Alcohol related disease mortality index
2. Poor decisions mortality index
Each index is computed as the unweighted sum of the z-scores for each of
the individual cause-specific mortality rates within each index.
z-scores are computed by subtracting the control group mean (i.e. the
mean mortality rate among wet state-years) and dividing by the control
group standard deviations.
The indices are in standard deviation units.
14

15. Why use summary indices?
1. Improves statistical power to detect effects if effects works in the same
direction Anderson, Michael (2008) ; Kling, Liebman and Katz (2007);
Hoynes, Whitmore and Almond (2016)
2. Deals with multiple hypothesis testing bias (aka “over-testing” or finding
statistically significant effects simply because we are considering more
outcomes).
Likelihood of finding a false positive does not increase as we add more
mortality outcomes to the index.
3. Helps account for misclassification of causes of death.
Medical science primitive in early 20th century.
15

16. Effect of early prohibition laws on alcohol related causes of
death
Alcoholism
Circulatory
disease
Cirrhosis
Infant
mortality
Liver
diseases
Peritonitis
Stomach
diseases
Ulcers
Disease
index
Share_Dry -2.410** -0.165 0.298 -2.732 -0.039 -0.064 -0.884 -0.251 -1.674**
(-0.494) (-4.988) (-0.547 (-7.166) (-0.212) (-0.444) (-0.91) (-0.191) (-0.603)
N 405 405 405 405 405 405 405 405 405
R-squared 0.854 0.944 0.935 0.961 0.864 0.925 0.915 0.823 0.95
16

17. Using the literature’s approach (Statewide_Dry_Enacted) to
measure prohibition
Alcoholism
Circulatory
disease
Cirrhosis
Infant
mortality
Liver
diseases
Peritonitis
Stomach
diseases
Ulcers
Disease
index
Statewid
e_Dry_
Enacted
-0.441 -6.179+ 0.283 3.418 0.104 -0.258 0.799 -0.15 -0.269
(-0.46) (-3.419) (-0.358) (-5.077) (-0.144) (-0.253) (-0.637) (-0.115) (-0.349)
N 405 405 405 405 405 405 405 405 405
R-
squared
0.834 0.945 0.935 0.961 0.864 0.925 0.915 0.823 0.948
17

18. Effect of early prohibition laws on poor decisions mortality
and all non-alcohol related causes
Accidents Homicides Suicides Syphilis
Decision
index
All other
causes
Share_Dry -6.528+ -1.342* -1.406 -0.178 -1.498+ -29.1
(-3.524) (-0.595) (-1.018) (-0.576) (-0.774) (-31.66)
N 404 405 405 405 405 405
R-squared 0.876 0.937 0.933 0.916 0.929 0.897
18
Using the literature’s measure of prohibition
Accidents Homicides Suicides Syphilis
Decisions
index
All other
causes
Statewide_Dr
y_Enacted
-1.322 -0.575 -0.735 -0.339 -0.742 -24.1
(-2.194) (-0.376) (-0.54) (-0.423) (-0.479) (-22.93)
N 404 405 405 405 405 405
R-squared 0.873 0.934 0.932 0.916 0.927 0.897