Does Smoking Keep You Slim? Evidence from Japan's Smoking Ban in the Workplace

• Published date: 01 September 2022
• Author: Junchao Zhang
• Date: 01 September 2022
• DOI: http://doi.org/10.1111/asej.12279

ORIGINAL ARTICLE

Does Smoking Keep You Slim? Evidence from Japan’s

Smoking Ban in the Workplace

Junchao Zhang

Niigata University, Niigata, Japan

Correspondence

Junchao Zhang, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, 950-2181, Niigata, Japan.

Email: zhang@econ.niigata-u.ac.jp

Funding information

Japan Society for the Promotion of Science, Grant/Award Numbers: KAKENHI 19K13710, 22K13384

Abstract

Long-term time-series data show a strong negative correlation between obesity and

smoking prevalence, which may not reflect the causality. Many heavy smokers claim that

smoking helps them maintain a slim body and keep smoking despite the health risks.

Using the Japan Household Panel Survey, this study investigates the causal effect

of smoking on body shapes by exogenous variations of Japan’s smoking ban in the

workplace. Contrary to previous studies, our instrumental variable estimates show that

smoking has no effect on body mass index, obesity and underweightness. We also

construct an overidentified model to test the robustness of our results.

KEYWORDS

BMI, instrumental variable, smoking, smoking ban

JEL CLASSIFICATION

I12, I18

1|INTRODUCTION

Every smoker knows the harm of smoking, but few can easily quit. Since the

health risks of smoking were first announced in a US Department of Health,

Education, and Welfare (1964) report by Surgeon General Luther Terry in the

United States, the US Government has taken aggressive actions, such as impos-

ing stricter minimum legal age limits, providing smoking cessation education

and implementing advertising regulations. In Japan, smoking is historically less

DOI: 10.1111/asej.12279

© 2022 East Asian Economic Association and John Wiley & Sons Australia, Ltd.

Received: 22 November 2021; Revised: 20 April 2022; Accepted: 9 May 2022

318 Asian Economic Journal. 2022;36:318–336.

wileyonlinelibrary.com/journal/asej

restricted by law than in many other countries. Smoking in public places had

not been made illegal in Japan until the Health Promotion Law was introduced

in 2003. As the country with the highest life expectancy in the world, Japan sur-

prisingly has the second-highest smoking prevalence among G7 countries, at

23.9% in 2011 (26.2% in France, 16.1% in the USA, 16.2% in Canada, 21.9% in

Germany, 21.5% in the UK and 23.1% in Italy; OECD 2011).

Smokers often claim that reducing cigarette use will make them gain weight,

and they keep smoking regardless of the health risks. Some studies have found

that female smokers refuse to quit smoking because of anxiety about weight

gain (Caan et al., 1996; White, 2012). A strong negative correlation over time

between smoking prevalence and obesity rates has been widely noticed and dis-

cussed. A similar trend has also been observed in Japan, which confuses

policymakers and makes smokers less motivated to quit smoking. Figures 1and

2show the long-term time-series data for smoking prevalence and the obesity

rate in Japan, respectively. Male smoking prevalence decreased from 70.2% in

1980 to 32.2% in 2013, but the male obesity rate increased from 17.8% in 1980

to 28.6% in 2013. Obesity is defined as a body mass index (BMI) of 25.0 or over

for the Japanese population, whereas it is defined as a BMI of 30.0 or over for

Western populations. The time trend of female smoking prevalence and the obe-

sity rate is different between the young and the elderly.

FIGURE 1 Smoking prevalence in Japan 1980–2013

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