david pritchard. bibliography.

Notes on Mills and Hamilton, Urban Economics [4]

• Traditional economic models pay no attention to space and distance. "In very advanced treatments of theory, in which consideration of time is basic, economists typically assume that space can be overcome costlessly or that all economic activity takes place at the same point." [p. 15]
• Economies of scale are limited by transportation costs. As scale increases, transportation distances (and costs) increase. This leads to an optimum scale, where transportation costs limit any further increase in size.
• Agglomeration economies have three reasons for existing:
  • law or large numbers: having many nearby customers (employers, employees etc.) allows fluctuations in outputs and inputs to be more easily absorbed
  • complementarities in production: items that can be better produced together than separately
  • innovation, drawing from Jane Jacobs' theories [2].
• Interesting comments on the limits of growth. Prerailroad transport depended on oceangoing vessels, which were 100 times cheaper than transport by land—so much so that most manufactured goods bought in America were imported from Europe! [pp. 21-22] Early cities rarely grew large—Rome reached a million, but this wasn't reachieved until Hangzhou in the twelfth century and later London in 1800. Ancient Athens peaked at 40 000.
• Urbanisation has decelerated since about 1930. [p. 55]
• 
  

  Table 1: Urban travel, 1940 to 1985. Sources: American Public Transit Association (1987) and Statistical Abstract of the United States (1987).

  	Public Transit Passengers (in millions)					Automobile (in billions of vehicle miles)
  Year	Railway	Subway	Trolley	Bus	Total
  1940	5943	2382	534	4239	13098	129.1
  1945	9426	2698	1244	9886	23254	109.5
  1950	3904	2264	1658	9420	17246	182.5
  1955	1207	1870	1202	7240	11529	224.5
  1960	463	1850	657	6425	9395	284.8
  1965	276	1858	305	5814	8253	378.2
  1970	235	1881	182	5034	7332	494.5
  1975	124	1673	78	5084	6972	609.6
  1980	133	2108	142	5837	8567	671.0
  1985	135	2297	139	6024	8948	n.a.

  
  

• Travellers' value of time can be observed when they change modes:

  Suppose, for example, that commuters who earn $10.00 per hour are observed to switch from bus to car if the time saving is ten minutes, even though the car trip costs $0.50 more than the bus trip. Then, the commuters are observed to value travel time at about $0.05 per minute, or at $3.00 per hour. In fact, this result is typical. Commuters typically value travel time in line haul vehicles at between one-third and one-half their wage rates [1]. Several studies, however, have shown that time spent walking to or waiting at transit stops is valued at two to four times the value placed on line haul travel time. Exposure to weather, noise, and fatigue probably account for the high value placed on such suburban collection times. Presumably, the same is true of downtown distribution times, although evidence is lacking. [pp. 260-261]

  I'd argue that downtown value of walking time is lower, since it's more enjoyable (visual stimulation), and can be very useful for trip-chaining.

• Keeler [3] estimated optimum San Francisco rush hour tolls at $0.09-$0.25 per vehicle mile on suburban roads, and $0.32-$0.91 for central-city freeways (1987 dollars). Keeler also estimated the relative viabilities of automobile, subway and bus networks for various population sizes, concluding that buses beat automobiles when corridor demand is 2000 passengers per hour, and subways beat automobiles at 20000 passengers per hour; subways never beat buses [p. 272].

• Despite the promising opening, this book completely ignores the effects of the automobile network on urban land use, and the subsequent effects on mode share. Sigh.

Bibliography

1

David A. Hensher.
Valuation of journey attributes: Existing empirical evidence.
In David A. Hensher and M.Q. Dalvi, editors, Identification and Valuation of Travel Choice Determinants. McGraw-Hill, New York City, NY, USA, 1977.

2

Jane Jacobs.
The Economy of Cities.
Vintage, New York City, NY, USA, 1970.

3

Theodore Keeler.
The Full Costs of Urban Transport.
Number 21 in Monograph. Institute of Urban & Regional Development, Berkeley, CA, USA, 1975.

4

Edwin S. Mills and Bruce W. Hamilton.
Urban Economics.
Harper Collins, New York City, NY, USA, 4th edition, 1989.