Harold Hotelling
Harold Hotelling  

Born 
Fulda, Minnesota, U.S. 
September 29, 1895
Died 
December 26, 1973 Chapel Hill, North Carolina, U.S. 
(aged 78)
Nationality  United States 
Alma mater 
Princeton University PhD 1924 University of Washington BA 1919, MA 1921 
Known for 
Hotelling's Tsquare distribution Canonical correlation analysis Hotelling's law Hotelling's lemma Hotelling's rule 
Awards  North Carolina Award 1972 
Scientific career  
Fields 
Statistics Economics 
Institutions 
Univ. of North Carolina 1946–73 Columbia University 1931–46 Stanford University 1927–31 
Doctoral advisor  Oswald Veblen 
Doctoral students 
Kenneth Arrow Seymour Geisser 
Influenced  Kenneth Arrow, Seymour Geisser, Milton Friedman 
Harold Hotelling (/ˈhoʊtəlɪŋ/; September 29, 1895 – December 26, 1973) was an American mathematical statistician and an influential economic theorist, known for Hotelling's law, Hotelling's lemma, and Hotelling's rule in economics, as well as Hotelling's Tsquared distribution in statistics.^{[1]} He also developed and named the principal component analysis method widely used in statistics and computer science.
He was Associate Professor of Mathematics at Stanford University from 1927 until 1931, a member of the faculty of Columbia University from 1931 until 1946, and a Professor of Mathematical Statistics at the University of North Carolina at Chapel Hill from 1946 until his death. A street in Chapel Hill bears his name. In 1972 he received the North Carolina Award for contributions to science.
Contents
Statistics
Hotelling is known to statisticians because of Hotelling's Tsquared distribution which is a generalization of the Student's tdistribution in multivariate setting, and its use in statistical hypothesis testing and confidence regions. He also introduced canonical correlation analysis.
At the beginning of his statistical career Hotelling came under the influence of R.A. Fisher, whose Statistical Methods for Research Workers had "revolutionary importance", according to Hotelling's review. Hotelling was able to maintain professional relations with Fisher, despite the latter's temper tantrums and polemics. Hotelling suggested that Fisher use the English word "cumulants" for Thiele's Danish "semiinvariants". Fisher's emphasis on the sampling distribution of a statistic was extended by Jerzy Neyman and Egon Pearson with greater precision and wider applications, which Hotelling recognized. Hotelling sponsored refugees from European antisemitism and Nazism, welcoming Henry Mann and Abraham Wald to his research group at Columbia. While at Hotelling's group, Wald developed sequential analysis and statistical decision theory, which Hotelling described as "pragmatism in action".
In the United States, Harold Hotelling is known for his leadership of the statistics profession, in particular for his vision of a statistics department at a university, which convinced many universities to start statistics departments. Hotelling was known for his leadership of departments at Columbia University and the University of North Carolina.
Economics
Hotelling has a crucial place in the growth of mathematical economics; several areas of active research were influenced by his economics papers. While at the University of Washington, he was encouraged to switch from pure mathematics toward mathematical economics by the famous mathematician Eric Temple Bell. Later, at Columbia University (where during 193334 he taught Milton Friedman statistics) in the '40s, Hotelling in turn encouraged young Kenneth Arrow to switch from mathematics and statistics applied to actuarial studies towards more general applications of mathematics in general economic theory. Hotelling is the eponym of Hotelling's law, Hotelling's lemma, and Hotelling's rule in economics.
Hotelling was influenced by the writing of Henry George and was an editorial adviser for the Georgist journal AJES^{[2]} Mason Gaffney claims that Hotelling kept his lifelong beliefs about land and tax reform secret because he feared ridicule.^{[3]}
Spatial economics
One of Hotelling’s most important contributions to economics was his conception of “spatial economics” in his 1929 article.^{[4]} Space was not just a barrier to moving goods around, but rather a field upon which competitors jostled to be nearest to their customers.^{[5]}
Hotelling considers a situation in which there are two sellers at point A and B in a line segment of size l. The buyers are distributed uniformly in this line segment and carry the merchandise to their home at cost c. Let p_{1} and p_{2} be the prices charged by A and B, and let the line segment be divided in 3 parts of size a, x+y and b, where x+y is the size of the segment between A and B, a the portion of segment to the left of A and b the portion of segment to the right of B. Therefore, a+x+y+b=l. Since the product being sold is a commodity, the point of indifference to buying is given by p_{1}+cx=p_{2}+cy. Solving for x and y yields:
Let q_{1} and q_{2} indicate the quantities sold by A and B. The sellers profit are:
By imposing profit maximization:
Hotelling obtains the economic equilibrium. Hotelling argues this equilibrium is stable even though the sellers may try to establish a price cartel.
Market socialism (Georgism)
As an extension of his research in spacial economics, Hotelling realized that it would be possible and socially optimal to finance investment in public goods through a Georgist land value tax and then provide such goods and services to the public at marginal cost (in many cases for free). This is an early expression of the Henry George theorem that Joseph Stiglitz and others expanded upon. Hotelling pointed out that when local public goods like roads and trains become congested, users create an additional marginal cost of excluding others. Hotelling became an early advocate of Georgist congestion pricing and stated that the purpose of this unique type of toll fee was in no way to recoup investment costs but was instead a way of changing behavior and compensating those who are excluded. Hotelling describes how human attention is also in limited supply at any given time and place, which produces a rental value; he concludes that billboards could be regulated or taxed on similar grounds as other scarcity rents. Hotelling reasoned that rent and taxation were analogous, the public and private versions of a similar thing. Therefore, the social optimum would be to put taxes directly on rent.^{[6]} Kenneth Arrow described this as 'market socialism', but Mason Gaffney points out that it is actually 'Georgism'.^{[7]} Hotelling added the following comment about the ethics of Georgist value capture: "The proposition that there is no ethical objection to the confiscation of the site value of land by taxation, if and when the nonlandowning classes can get the power to do so, has been ably defended by [the Georgist] H. G. Brown."^{[6]}
Nonconvexities
Hotelling made pioneering studies of nonconvexity in economics. In economics, nonconvexity refers to violations of the convexity assumptions of elementary economics. Basic economics textbooks concentrate on consumers with convex preferences and convex budget sets and on producers with convex production sets; for convex models, the predicted economic behavior is well understood.^{[8]}^{[9]} When convexity assumptions are violated, then many of the good properties of competitive markets need not hold: Thus, nonconvexity is associated with market failures,^{[10]}^{[11]} where supply and demand differ or where market equilibria can be inefficient.^{[8]}^{[11]}^{[12]}^{[13]}^{[14]}^{[15]}
Producers with increasing returns to scale: Marginal cost pricing
In "oligopolies" (markets dominated by a few producers), especially in "monopolies" (markets dominated by one producer), nonconvexities remain important.^{[15]} Concerns with large producers exploiting market power initiated the literature on nonconvex sets, when Piero Sraffa wrote about firms with increasing returns to scale in 1926,^{[16]} after which Hotelling wrote about marginal cost pricing in 1938.^{[17]} Both Sraffa and Hotelling illuminated the market power of producers without competitors, clearly stimulating a literature on the supplyside of the economy.^{[18]}
Consumers with nonconvex preferences
When the consumer's preference set is nonconvex, then (for some prices) the consumer's demand is not connected; A disconnected demand implies some discontinuous behavior by the consumer, as discussed by Hotelling:
If indifference curves for purchases be thought of as possessing a wavy character, convex to the origin in some regions and concave in others, we are forced to the conclusion that it is only the portions convex to the origin that can be regarded as possessing any importance, since the others are essentially unobservable. They can be detected only by the discontinuities that may occur in demand with variation in priceratios, leading to an abrupt jumping of a point of tangency across a chasm when the straight line is rotated. But, while such discontinuities may reveal the existence of chasms, they can never measure their depth. The concave portions of the indifference curves and their manydimensional generalizations, if they exist, must forever remain in unmeasurable obscurity.^{[19]}
according to Diewert.^{[20]}
Following Hotelling's pioneering research on nonconvexities in economics, research in economics has recognized nonconvexity in new areas of economics. In these areas, nonconvexity is associated with market failures, where any equilibrium need not be efficient or where no equilibrium exists because supply and demand differ.^{[8]}^{[11]}^{[11]}^{[12]}^{[13]}^{[14]}^{[15]} Nonconvex sets arise also with environmental goods (and other externalities),^{[13]}^{[14]} and with market failures,^{[10]} and public economics.^{[12]}^{[21]} Nonconvexities occur also with information economics,^{[22]} and with stock markets^{[15]} (and other incomplete markets).^{[23]}^{[24]} Such applications continued to motivate economists to study nonconvex sets.^{[8]}
Legacy
Harold was survived by seven children and many grandchildren. ^{[25]}
Works
 Hotelling, Harold (September 1925). "A general mathematical theory of depreciation". Journal of the American Statistical Association. Taylor and Francis. 20 (151): 340–353. doi:10.1080/01621459.1925.10503499.
 Hotelling, Harold (September 1927). "Differential equations subject to error, and population estimates". Journal of the American Statistical Association. Taylor and Francis. 22 (159): 283–314. doi:10.1080/01621459.1927.10502963.
 Hotelling, Harold (September 1927). "Statistical methods for research workers by R. A. Fisher". Journal of the American Statistical Association. Taylor and Francis via JSTOR. 22 (159): 411–412. doi:10.2307/2276824. JSTOR 2276824. PMC 1708459. Harold Hotelling’s review of Fishers’ Statistical methods for research workers.
 Hotelling, Harold; Working, Holbrook (March 1929). "Applications of the theory of error to the interpretation of trends". Journal of the American Statistical Association, special issue: Proceedings of the American Statistical Association. Taylor and Francis. 24 (165A): 73–85. doi:10.1080/01621459.1929.10506274.
 Hotelling, Harold (March 1929). "Stability in competition". The Economic Journal. Taylor and Francis. 39 (153): 41–57. doi:10.2307/2224214. JSTOR 2224214.
 Hotelling, Harold (April 1931). "The economics of exhaustible resources". Journal of Political Economy. The University of Chicago Press via JSTOR. 39 (2): 137–175. doi:10.1086/254195. JSTOR 1822328.
 Hotelling, Harold (1931). "The generalization of student's ratio". Annals of Mathematical Statistics. Institute of Mathematical Statistics. 2 (3): 360–378. doi:10.1214/aoms/1177732979.
 Hotelling, Harold (October 1932). "Edgeworth's taxation paradox and the nature of demand and supply functions". Journal of Political Economy. The University of Chicago Press via JSTOR. 40 (5): 577–616. doi:10.1086/254387. JSTOR 1822600.
 Hotelling, Harold (September 1933). "Analysis of a complex of statistical variables into principal components". Journal of Educational Psychology. American Psychological Association. 24 (6): 417–441. doi:10.1037/h0071325.
 Hotelling, Harold (October 1933). "Note on Edgeworth's taxation phenomenon and Professor Garver's additional condition on demand functions". Econometrica. The Econometric Society via JSTOR. 1 (4): 408–409. doi:10.2307/1907332. JSTOR 1907332.
 Hotelling, Harold (January 1935). "Demand functions with limited budgets". Econometrica. The Econometric Society via JSTOR. 3 (1): 66–78. doi:10.2307/1907346. JSTOR 1907346.
 Hotelling, Harold (February 1935). "The most predictable criterion". Journal of Educational Psychology. American Psychological Association. 26 (2): 139–142. doi:10.1037/h0058165.
 Hotelling, Harold (December 1936). "Relation between two sets of variates". Biometrika. Oxford Journals. 28 (3–4): 321–377. doi:10.1093/biomet/28.34.321.
 Hotelling, Harold; Pabst, Margaret R. (March 1936). "Rank correlation and tests of significance involving no assumption of normality". Annals of Mathematical Statistics. Institute of Mathematical Statistics. 7 (1): 29–43. doi:10.1214/aoms/1177732543. JSTOR 2957508.
 Hotelling, Harold (July 1938). "The general welfare in relation to problems of taxation and of railway and utility rates". Econometrica. The Econometric Society. 6 (3): 242–269. doi:10.2307/1907054. JSTOR 1907054.
 Hotelling, Harold (December 1940). "The teaching of statistics". Annals of Mathematical Statistics. Institute of Mathematical Statistics. 11 (4): 457–470. doi:10.1214/aoms/1177731833.
 Hotelling, Harold (1951). "A generalized TTest and measure of multivariate dispersion". Proceedings of the Second Berkeley Symposium on Mathematical Statistics and Probability. University of California Press: 23–41.
 Hotelling, Harold (March 1951). "The impact of R. A. Fisher on statistics". Journal of the American Statistical Association. Taylor and Francis. 46 (253): 35–46. doi:10.1080/01621459.1951.10500765.
 Hotelling, Harold (1988). "Golden oldies: classic articles from the world of statistics and probability: 'the teaching of statistics'". Annals of Mathematical Statistics. Institute of Mathematical Statistics. 3 (1): 63–71. doi:10.1214/ss/1177013001.
 Hotelling, Harold (1988). "Golden oldies: classic articles from the world of statistics and probability: 'the place of statistics in the university'". Annals of Mathematical Statistics. Institute of Mathematical Statistics. 3 (1): 72–83. doi:10.1214/ss/1177013002.
Papers
 "Harold Hotelling papers, 19101975". Columbia University Libraries Archival Collections. Retrieved 20131205.
References
 ^ Dodge, Y. (2008). The concise encyclopedia of statistics, Springer
 ^ Turgeon, Lynn. Bastard Keynesianism : the evolution of economic thinking and policymaking since World War II. Westport, Conn: Praeger, 1997
 ^ Gaffney, Mason. "Warm Memories of Bill Vickrey". Land & Liberty. http://www.cooperativeindividualism.org/gaffneymason_warmmemoriesofbillvickrey1997.htm
 ^ Hotelling, Harold (1929). "Stability in Competition". Economic Journal. 39 (153): 41–57. doi:10.2307/2224214.
 ^ Palda, Filip (2013). The Apprentice Economist: Seven Steps to Mastery. Toronto. CooperWolfling Press.
 ^ ^{a} ^{b} Hotelling, Harold (1938). "The General Welfare in Relation to Problems of Taxation and of Railway and Utility Rates". Econometrica. 6 (3): 242–269. doi:10.2307/1907054. JSTOR 1907054.
 ^ Gaffney, Mason, and Fred Harrison. The corruption of economics. London: ShepheardWalwyn in association with Centre for Incentive Taxation, 2006
 ^ ^{a} ^{b} ^{c} ^{d} MasColell, A. (1987). "Nonconvexity". In Eatwell, John; Milgate, Murray; Newman, Peter. The New Palgrave: A Dictionary of Economics (PDF) (new ed.). Palgrave Macmillan. pp. 653–661. doi:10.1057/9780230226203.3173.
 ^ Green, Jerry; Heller, Walter P. (1981). "1 Mathematical analysis and convexity with applications to economics". In Arrow, Kenneth Joseph; Intriligator, Michael D. Handbook of mathematical economics, Volume I. Handbooks in economics. 1. Amsterdam: NorthHolland Publishing Co. pp. 15–52. doi:10.1016/S15734382(81)010059. ISBN 0444861262. MR 0634800.
 ^ ^{a} ^{b} Salanié, Bernard (2000). "7 Nonconvexities". Microeconomics of market failures (English translation of the (1998) French Microéconomie: Les défaillances du marché (Economica, Paris) ed.). Cambridge, MA: MIT Press. pp. 107–125. ISBN 9780262194433.
 ^ ^{a} ^{b} ^{c} ^{d} Salanié (2000, p. 36)

^ ^{a} ^{b} ^{c} Pages 63–65: Laffont, JeanJacques (1988). "3 Nonconvexities". Fundamentals of public economics. MIT. ISBN 9780262121279. External link in
publisher=
(help)  ^ ^{a} ^{b} ^{c} Starrett, David A. (1972). "Fundamental nonconvexities in the theory of externalities". Journal of Economic Theory. 4 (2): 180–199. doi:10.1016/00220531(72)901482. MR 0449575.
 ^ ^{a} ^{b} ^{c} Pages 106, 110–137, 172, and 248: Baumol, William J.; Oates, Wallace E.; with contributions by V. S. Bawa and David F. Bradford (1988). "8 Detrimental externalities and nonconvexities in the production set". The Theory of environmental policy (Second ed.). Cambridge: Cambridge University Press. pp. x+299. doi:10.2277/0521311128. ISBN 9780521311120.
 ^ ^{a} ^{b} ^{c} ^{d} Page 1: Guesnerie, Roger (1975). "Pareto optimality in nonconvex economies". Econometrica. 43: 1–29. doi:10.2307/1913410. JSTOR 1913410. MR 0443877. (Guesnerie, Roger (1975). "Errata". Econometrica. 43 (5–6): 1010. doi:10.2307/1911353. JSTOR 1911353. MR 0443878.)
 ^ Sraffa, Piero (1926). "The Laws of returns under competitive conditions". Economic Journal. 36 (144): 535–550. JSTOR 2959866.
 ^ Hotelling, Harold (July 1938). "The General welfare in relation to problems of taxation and of railway and utility rates". Econometrica. 6 (3): 242–269. doi:10.2307/1907054. JSTOR 1907054.
 ^ Pages 5–7: Quinzii, Martine (1992). Increasing returns and efficiency (Revised translation of (1988) Rendements croissants et efficacité economique. Paris: Editions du Centre National de la Recherche Scientifique ed.). New York: Oxford University Press. pp. viii+165. ISBN 0195065530.
 ^ Hotelling (1935, p. 74): Hotelling, Harold (January 1935). "Demand functions with limited budgets". Econometrica. 3 (1): 66–78. doi:10.2307/1907346. JSTOR 1907346.
 ^ Diewert (1982, pp. 552–553): Diewert, W. E. (1982). "12 Duality approaches to microeconomic theory". In Arrow, Kenneth Joseph; Intriligator, Michael D. Handbook of mathematical economics, Volume II. Handbooks in economics. 1. Amsterdam: NorthHolland Publishing Co. pp. 535–599. doi:10.1016/S15734382(82)020074. ISBN 9780444861276. MR 0648778.
 ^ Starrett discusses nonconvexities in his textbook on public economics (pages 33, 43, 48, 56, 70–72, 82, 147, and 234–236): Starrett, David A. (1988). Foundations of public economics. Cambridge economic handbooks. Cambridge: Cambridge University Press. ISBN 9780521348010.
 ^ Radner, Roy (1968). "Competitive equilibrium under uncertainty". Econometrica. 36: 31–53. doi:10.2307/1909602.
 ^ Page 270: Drèze, Jacques H. (1987). "14 Investment under private ownership: Optimality, equilibrium and stability". In Drèze, J. H. Essays on economic decisions under uncertainty. Cambridge: Cambridge University Press. pp. 261–297. ISBN 0521264847. MR 0926685. (Originally published as Drèze, Jacques H. (1974). "Investment under private ownership: Optimality, equilibrium and stability". In Drèze, J. H. Allocation under Uncertainty: Equilibrium and Optimality. New York: Wiley. pp. 129–165.)
 ^ Page 371: Magill, Michael; Quinzii, Martine (1996). "6 Production in a finance economy". The Theory of incomplete markets (31 Partnerships ed.). Cambridge, Massachusetts: MIT Press. pp. 329–425.
 ^ Recollection from family member
 Arrow, Kenneth J. (1987). "Hotelling, Harold". The New Palgrave: A Dictionary of Economics. 2: 670–71.
 I. Olkina and A. R. Sampsonb (2001). "Hotelling, Harold (1895–1973)," International Encyclopedia of the Social & Behavioral Sciences, pp. 6921–6925. Abstract.
External links
 Harold Hotelling at the Mathematics Genealogy Project
 New School: Harold Hotelling
 American Statistical Association: Harold Hotelling
 Harold Hotelling
The following have photographs:
 Harold Hotelling on the Portraits of Statisticians page.
 National Academy of Sciences Biographical Memoir
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