David Hummels
Biographic Data
| ID | 1456138 |
|---|---|
| NAME | David Hummels |
| GIVEN NAMES | David |
| FAMILY NAME | Hummels |
| SIGNATURE | HUMMELS D |
| AFFILIATIONS | Purdue University West Lafayette |
| ORCID | 0000-0002-0280-8260 |
| VERIFIED | Yes |
| TOTAL WORKS | 11 |
| TOTAL CITATIONS | 71 |
| AUTHOR COUNT | 11 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1984 |
| LATEST PUBLICATION YEAR | 2025 |
| H-INDEX | 3 |
No Pain, No Gain
We employ Danish worker-firm data to study the effect of rising workload on health. Using both within-job-spell regression analyses and cohort event studies, we show that increases in firm sales lead workers to log longer hours and experience higher probabilities of stress, depression, heart disease, and strokes, with more pronounced effects for high-risk groups such as older workers, job-strained workers, and those with long initial work hours. …
Bridging the Divide
Rising partisan polarization in the American public over the last decade has been linked to stress and anxiety, raising questions about how communities and public health experts should respond. As the strength of an individual’s social network correlates with better health outcomes, could building a diverse set of connections moderate the effect of political polarization on an individual’s health? This study examines the role of social capital as…
The Wage Effects of Offshoring
We employ data that match the population of Danish workers to the universe of private-sector Danish firms, with product-level trade flows by origin- and destination-countries. We document new stylized facts about offshoring and instrument for offshoring and exporting. Within job spells, offshoring increases (decreases) the high-skilled ( low-skilled) wage; exporting increases the wages of all skill-types; the net wage-effect of trade varies subst…
Time as a Trade Barrier
A large and growing share of world trade travels by air. We model exporters' choice between fast, expensive air cargo and slow, cheap ocean cargo, which depends on the price elasticity of demand and the value that consumers attach to fast delivery. We use US imports data that provide rich variation in the premium paid for air shipping and in time lags for ocean transit to extract consumers' valuation of time. We estimate that each day in transit …
The trade reducing effects of market power in international shipping
Transportation Costs and International Trade in the Second Era of Globalization
While the precise causes of postwar trade growth are not well understood, declines in transport costs top the lists of usual suspects. However, there is remarkably little systematic evidence documenting the decline. This paper brings to bear an eclectic mix of data in order to provide a detailed accounting of the time-series pattern of shipping costs. The ad-valorem impact of ocean shipping costs is not much lower today than in the 1950s, with te…
The Variety and Quality of a Nation's Exports
Large economies export more in absolute terms than do small economies. We use data on shipments by 126 exporting countries to 59 importing countries in 5,000 product categories to answer the question: How? Do big economies export larger quantities of each good (the intensive margin), a wider set of goods (the extensive margin), or higher-quality goods? We find that the extensive margin accounts for around 60 percent of the greater exports of larg…
Shipping the Good Apples Out? An Empirical Confirmation of the Alchian‐Allen Conjecture
Alchian and Allen show that a per unit transactions cost lowers the relative price of, and raises the relative demand for, high‐quality goods. We extend their theory, deriving a relationship between per unit and ad valorem trade costs and the quality composition of trade. Detailed international trade data for many importers and exporters are used to test these predictions. Within a narrowly defined commodity classification, exporters charge desti…
Intranational Home Bias
Wolf demonstrates that trade within the United States appears substantially impeded by state borders. We revisit this finding with improved data. We show that much intranational home bias can be explained by wholesaling activity. Shipments by wholesalers are much more localized within states than shipments from manufacturing establishments. Controlling for relative prices and the use of actual, rather than imputed, shipment distances also reduces…
The nature and growth of vertical specialization in world trade
The Collector's Guide to the American Musical Theatre
Shipping the Good Apples Out? An Empirical Confirmation of the Alchian‐Allen Conjecture
Alchian and Allen show that a per unit transactions cost lowers the relative price of, and raises the relative demand for, high‐quality goods. We extend their theory, deriving a relationship between per unit and ad valorem trade costs and the quality composition of trade. Detailed international trade data for many importers and exporters are used to test these predictions. Within a narrowly defined commodity classification, exporters charge desti…
Transportation Costs and International Trade in the Second Era of Globalization
While the precise causes of postwar trade growth are not well understood, declines in transport costs top the lists of usual suspects. However, there is remarkably little systematic evidence documenting the decline. This paper brings to bear an eclectic mix of data in order to provide a detailed accounting of the time-series pattern of shipping costs. The ad-valorem impact of ocean shipping costs is not much lower today than in the 1950s, with te…
Bridging the Divide
Rising partisan polarization in the American public over the last decade has been linked to stress and anxiety, raising questions about how communities and public health experts should respond. As the strength of an individual’s social network correlates with better health outcomes, could building a diverse set of connections moderate the effect of political polarization on an individual’s health? This study examines the role of social capital as…
The trade reducing effects of market power in international shipping
The Collector's Guide to the American Musical Theatre
The nature and growth of vertical specialization in world trade
Intranational Home Bias
Wolf demonstrates that trade within the United States appears substantially impeded by state borders. We revisit this finding with improved data. We show that much intranational home bias can be explained by wholesaling activity. Shipments by wholesalers are much more localized within states than shipments from manufacturing establishments. Controlling for relative prices and the use of actual, rather than imputed, shipment distances also reduces…
Shipping the Good Apples Out? An Empirical Confirmation of the Alchian‐Allen Conjecture
Alchian and Allen show that a per unit transactions cost lowers the relative price of, and raises the relative demand for, high‐quality goods. We extend their theory, deriving a relationship between per unit and ad valorem trade costs and the quality composition of trade. Detailed international trade data for many importers and exporters are used to test these predictions. Within a narrowly defined commodity classification, exporters charge desti…
The Variety and Quality of a Nation's Exports
Large economies export more in absolute terms than do small economies. We use data on shipments by 126 exporting countries to 59 importing countries in 5,000 product categories to answer the question: How? Do big economies export larger quantities of each good (the intensive margin), a wider set of goods (the extensive margin), or higher-quality goods? We find that the extensive margin accounts for around 60 percent of the greater exports of larg…
Transportation Costs and International Trade in the Second Era of Globalization
While the precise causes of postwar trade growth are not well understood, declines in transport costs top the lists of usual suspects. However, there is remarkably little systematic evidence documenting the decline. This paper brings to bear an eclectic mix of data in order to provide a detailed accounting of the time-series pattern of shipping costs. The ad-valorem impact of ocean shipping costs is not much lower today than in the 1950s, with te…
The trade reducing effects of market power in international shipping
Time as a Trade Barrier
A large and growing share of world trade travels by air. We model exporters' choice between fast, expensive air cargo and slow, cheap ocean cargo, which depends on the price elasticity of demand and the value that consumers attach to fast delivery. We use US imports data that provide rich variation in the premium paid for air shipping and in time lags for ocean transit to extract consumers' valuation of time. We estimate that each day in transit …
The Wage Effects of Offshoring
We employ data that match the population of Danish workers to the universe of private-sector Danish firms, with product-level trade flows by origin- and destination-countries. We document new stylized facts about offshoring and instrument for offshoring and exporting. Within job spells, offshoring increases (decreases) the high-skilled ( low-skilled) wage; exporting increases the wages of all skill-types; the net wage-effect of trade varies subst…
Bridging the Divide
Rising partisan polarization in the American public over the last decade has been linked to stress and anxiety, raising questions about how communities and public health experts should respond. As the strength of an individual’s social network correlates with better health outcomes, could building a diverse set of connections moderate the effect of political polarization on an individual’s health? This study examines the role of social capital as…
No Pain, No Gain
We employ Danish worker-firm data to study the effect of rising workload on health. Using both within-job-spell regression analyses and cohort event studies, we show that increases in firm sales lead workers to log longer hours and experience higher probabilities of stress, depression, heart disease, and strokes, with more pronounced effects for high-risk groups such as older workers, job-strained workers, and those with long initial work hours. …
Economics (10 works) · Global trade and economics (8 works) · International economics (5 works) · International trade (5 works) · Business (4 works) · Demographic economics (4 works) · Microeconomics (3 works) · Defense, Military, and Policy Studies (2 works) · Econometrics (2 works) · Economic Growth and Productivity (2 works)