Document file:///D|/Export1/www.netlibrary.com/nlreader/nlreader.dll ...

More documents

Recommendations

Info

Document Appendix Page 89 In lecture 2, I concluded by alluding to recent modeling work of mine that seems both to validate and to integrate several of the ''outcast" traditions in economic geography: central-place theory, the market potential approach, and the idea of circular and cumulative causation. In this appendix I present the basic model that I have been using to explore these traditions. Parts of this approach have been published elsewhere; I first examined a two-location version of the model in Krugman (1991), explored the possibilities of a single-city economy and showed the usefulness of the market potential approach in Krugman (1993b), and showed how cumulative processes can lead to an approximate central-place outcome in Krugman (1993a). Here I offer an integrated treatment, of which all of these results can be seen as special cases. While the model is simple in conception, and the results we get are quite intuitive, sometimes the dynamic analysis defies paper-and-pencil analytics. Thus the approach relies heavily on numerical examples. This is currently an unfashionable theoretical technique, but as we will see it is highly productive in this case. file:///D|/Export2/www.netlibrary.com/nlreader/nlreader.dll@bookid=409&filename=page_89.html [4/18/2007 10:30:41 AM]
Document The Basic Approach Page 90 Any interesting model of economic geography must exhibit a tension between two kinds of forces: "centripetal" forces that tend to pull economic activity into agglomerations, and "centrifugal" forces that tend to break up such agglomerations or limit their size. There is a well-developed literature in urban economics, largely deriving from the work of Henderson (1974), in which a system of cities evolves from such a tension. In Henderson-type models, the centripetal force arises from assumed localized external economies in production; the centrifugal force is urban land rent. Together with assumptions about the process of city formation, Henderson's approach yields a model of the number and sizes of cities (though not of their location relative to one another). There is a variant of this approach, represented for example by Fujita (1988), in which external economies are not assumed but instead derived from increasing returns in a monopolistically competitive industry producing nontraded inputs. This leaves the basic approach unchanged, and still leaves the spatial relationship of cities to each other undetermined. In my own work, I have tried a somewhat different approach. No special assumptions are made either about localized external economies or nontradeability. Indeed, cities are not primitive concepts in the model. Instead, agglomerations emerge from the interaction between increasing returns at the level of the individual production facility transportation costs, and factor mobility. Because of increasing returns, it is advantageous to concentrate production of each good at a few locations. Because of transportation file:///D|/Export2/www.netlibrary.com/nlreader/nlreader.dll@bookid=409&filename=page_90.html [4/18/2007 10:30:42 AM]
Page 1 and 2:
Document file:///D|/Export1/www.net
Page 3 and 4:
Document Fourth printing, 1998 Firs
Page 5 and 6:
Document Preface Page vii This book
Page 7 and 8:
Document Page ix limiting nature of
Page 9 and 10:
Document coastline of Africa was fi
Page 11 and 12:
Document What links development and
Page 13 and 14:
Document Page 6 how our notion of w
Page 15 and 16:
Document The Big Push Page 8 A good
Page 17 and 18:
Document Demand Demand for the N go
Page 19 and 20:
Document Page 12 But even if the ec
Page 21 and 22:
Document Page 14 modern sector, the
Page 23 and 24:
Document Page 16 After 1960, by con
Page 25 and 26:
Document Page 18 sounds as if it mu
Page 27 and 28:
Document Page 20 and development in
Page 29 and 30:
Document Page 22 In fact, the conce
Page 31 and 32:
Document much less exciting career.
Page 33 and 34:
Document Page 26 paper that made pe
Page 35 and 36:
Document Page 28 The exception prov
Page 37 and 38:
Document 2 Geography Lost and Found
Page 39 and 40:
Document Page 33 In the previous le
Page 41 and 42:
Document Page 35 So why did spatial
Page 43 and 44: Document economies because they kne
Page 45 and 46: Document market areas should be hex
Page 47 and 48: Document Page 41 But why didn't som
Page 49 and 50: Document Page 43 in economics. I ca
Page 51 and 52: Document 0045-01.gif Page 45 where
Page 53 and 54: Document Page 47 such as the U.S. m
Page 55 and 56: Document Page 49 Pred's story is es
Page 57 and 58: Document Page 51 of individual maxi
Page 59 and 60: Document Page 53 outweighs any othe
Page 61 and 62: Document economists, it was not eno
Page 63 and 64: Document Page 57 intellectual devic
Page 65 and 66: Document Page 59 fact is that most
Page 67 and 68: Document Page 61 stories that are n
Page 69 and 70: Document Page 63 course, central pl
Page 71 and 72: Document only piece of spatial econ
Page 73 and 74: Document Page 68 This surely sounds
Page 75 and 76: Document succeeds in explaining or
Page 77 and 78: Document your model can represent a
Page 79 and 80: Document Page 74 vociferous critics
Page 81 and 82: Document Page 76 farmer if the extr
Page 83 and 84: Document insights, like the insulat
Page 85 and 86: Document In fact, we are all builde
Page 87 and 88: Document sophisticated, some neglec
Page 89 and 90: Document Page 84 legitimized the ro
Page 91 and 92: Document Should we completely ignor
Page 93: Document Page 88 theory, I believe
Page 97 and 98: Document Harris showed that the tra
Page 99 and 100: Document Page 94 emerge as a conseq
Page 101 and 102: Document Page 96 "iceberg" form int
Page 103 and 104: Document Page 98 force. In particul
Page 105 and 106: Document We now have a soluble set
Page 107 and 108: Document Page 102 This desire to ge
Page 109 and 110: Document Figure A.1 have also chose
Page 111 and 112: Document Page 106 (The number 12 wa
Page 113 and 114: Document some extent even in terms
Page 115 and 116: Document presented me with a T-shir
Page 117 and 118: Document Page 112 Krugman, P. 1991.
Page 119 and 120: Document Central-place theory, 38-3
Page 121 and 122: Document Dicken, P., Location in Sp
Page 123 and 124: Document Galbraith, John Kenneth, 4
Page 125 and 126: Document backward and forward, 17,
Page 127 and 128: Document Models, modeling in develo
Page 129 and 130: Document Rural sector, 48. See also
Page 131 and 132: Document Transportation, 36 U marke
show all

Document file:///D|/Export1/www.netlibrary.com/nlreader/nlreader.dll ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?