RESEARCH PAPER

Purchase Flow of Agricultural Raw Materials in the IX Region,

B. Schnettler Departamento de Producción Agropecuaria Universidad de Casilla 54-D Temuco, Chile

Abstract

B. Schnettler. Purchase flow of agricultural raw materials in the IX Region, Chile. The objectives of this study were to evaluate purchase flows of agricultural raw materials and to establish the commercial boundaries of the city of Temuco in the IX Region of Chile in 2002-2003. Local Planning Boards were polled from the districts of the IX Region and in the of Arauco, Biobio and were also included. The gravitational determinist model on demarcation of commercial areas was used. According to the results obtained, the city of Temuco, as leader city, attracts expense flow from all of the neighbouring districts in the IX Region and also from border districts in the VIII and X Regions, totalizing 35 districts, north and south of Temuco. There were shared zones of attraction with Valdivia, Concepcion and Los Angeles. The coefficients of the population variables and number of commercial patents used to measure the commercial attraction of the districts of origin on the expense flows were negative. The coefficients for population, number of commercial patents and sales area of the districts of destination of flows were positive, whereas both restriction variables had negative coefficients. The coefficients of the three variables were statistically significant (p < 0.05) in the specification of the gravitational model that uses population as an attribute of the district of origin, destination of the commercial flows and travel time as restriction variables. The global adjustment of the model improved when other variables that reflected the commercial attraction of the procurement centers were introduced, i.e. number of business patents of agricultural supply stores and the related commercial area, showing determination coefficients higher than 40%, considered acceptable in this type of research. Not withstanding, the variable referred to the district of origin of the expense re-routing had statistically non-significant coefficients (p>0.05) and were positive for the commercial area. Therefore, It was determined that movement of raw material acquisitions outside the district where farms were located is done in the interurban commercial centres, that offered the largest variety of products, and the best business conditions and services to farmers.

Key words: Commercial flows, commercial gravitation, raw materials. Cien. Inv. Agr. 32(3). 177-189. 2005

INTRODUCTION product (GIP) of the VIII, IX and X has varied from 7 to 14% between The economical contribution of the agrarian 1996 and 2000. The participation of the and forestry sector to the annual gross internal business sector to regional GIP represented

Received on 29 December 2004; Accepted on 13 September 2005. 1 Dirigir correspondencia a B. Schnettler: [email protected] 178 CIENCIA E INVESTIGACION AGRARIA

8 to 10% approximately for the same period analytical models or empiric methods. These (Central Bank of Chile, 2003). These methods consist on surveys to determine economic sectors are linked to the agricultural the buying habits of the consumers and the production. The business sector provides importance of the corresponding expense seeds, fertilizers, herbicides, insecticides, flows. These procedures may be oriented fungicides and other supplies that are required to the consumers themselves or, to those for annual and permanent crop production. familiar with the purchasing habits of the Today, transportation and toll fees are inhabitants of a given area (De Juan, 1998; considerably relevant as part of the direct Casares and Rebollo, 2000). costs of production. Therefore, the acquisitions of most of the supplies are made The analytical or theoretical methods can within the area where farms are located, and be used to determine the geographical size very seldom purchases are done in business and degree of commercial attraction that a centers far way from the farm. specific shopping center exerts. These methods are based on the establishment of The business areas appeared as results of consumer behavior models and estimating the interregional movement. These areas their corresponding parameters. Such correspond to rather extended zones where models may be based on normative inhabitants of diverse population nuclei hypothesis concerning consumer travel gravitate. Usually and preferentially, these practices, using information obtained zones are located in an urban center that through behavior analysis or, evaluating has a large and well-supplied commerce. consumer usefulness functions using According to this definition part of the techniques of joint measures (Craig et al. commercial expenditure, pertaining to the 1984). total amount consumers allot to retail good acquisition, minus service expenditures, is Among the models based on normative eluded between locations. In other words, hypotheses, the theory of central place it accounts for the presence of purchase development proposed by Christaller (1933) flows or commercial flows. These occur and Lösch (1954) are important. Similarly, due to the uneven distribution of the law of retail gravitation (Reilly, 1931), commercial installations throughout the and its derived (Converse, 1949) are also territory, reflecting the heterogeneous important. Among the models that use distribution of demand and profitability information revealed by the consumer, needs of retail companies. Ultimately, Huff’s proposal (1964) for retail attraction commercial areas exist due to commercial is the most frequently used. He establishes flows that correspond to consumer a probabilistic and disaggregated model of purchasing transfer required by the lack of commercial attraction of establishments, adequate commercial product supply, leading to new stochastic models. With the needed to satisfy their demand. generalization of the previous models, arise the multiplicative models of competitive Studying purchase flows, and commercial interaction thus opening a new line of area development, would enable to solve research (Nakanishi and Cooper, 1974). effectively and efficiently the location These contributions are the basis of spatial problems in the private sector. At the same interaction models, among which the most time, would enable to choose the recent ones are those of Fotheringham and distribution channels for businesspersons O«Kelly (1989); Gil et al. (1997); Mas and producers. These can be studied using (1999) and O«Kelly (1999). VOL 32 N°3 SEPTEMBER - DECEMBER 2005. 179

To select a shopping center, consumer Materials and methods behavior will depend on attraction and dissuasion variables. These may promote The equation proposed by Converse (1949), and hinder consumer movement back and known as the point of rupture or equivalent forth. The restriction variable relates to the attraction (DA-C), was used to obtain the distance and time that the consumer must study units for later surveys on purchase travel for purchasing, while attraction flows. This equation establishes the point variables relate to the size of the commercial of indifference for consumers between two establishments. Retail attraction assessment cities, and it gives the distance from a point has been based on the frequency with which of indifference to city A, being possible people use the shopping centers, and obtained the DB-C value. Mathematically increasingly on the size of the retail store. was expressed by the following equation: The reasoning behind this idea is that the larger the size of the store, or a group of stores, the larger the variety of products (1) offered. Thus, the consumer is certain to find the needed items. Therefore, consumers reduce the risk of wasted travel time given Where, DA-C; DB-C was the point of that larger shopping centers offer more indifference from city A, to city B; d, was variety of stores to choose from (La Forge the distance between city A and city B et al., 1984; Medina, 1997). Consequently, along the main road; PA was the population the consumer is willing to travel longer of city A, PB was the population of city B. distances in order to choose centers that offer lower travel costs, thus making larger The point of indifference was calculated shopping centers more attractive. between Temuco and the neighboring cities of Los Angeles (population 166.556, capital Numerous researchers have studied in detail of Biobío , VIII Region) and distance as to variable of gravitational models. Valdivia (140.559 inhabitants, capital of (Mayo et al., 1988). Buying implies traveling the Province of Valdivia, X Region) in the and consequently additional costs in terms of south. Temuco had 245.347 inhabitants time and money. Therefore, longer distances (INE, 2003), located 158.2 and 171.6 km between businesses and consumers have a away from Los Angeles and Valdivia, negative impact on the attraction exerted on respectively. Thus, the point of indifference them. Distance becomes to determining factor to the north was located at 86.7 km from in consumer choice, the impact of which Temuco (Collipulli District, IX Region), should be considered jointly with other and 97.7 km to the south (Lanco District, characteristic attributes of points of salesX Region). However, due to the (Fotheringham and O’Kelly, 1989). deterministic character of the model used, the empiric research was extended beyond Considering the importance of agricultural the limits previously indicated. This activity of the IX Region of Chile and those included the commercial flows of all 60 in the neighbor localities, the objective of Districts of the Region of Araucanía, this study was to establish the commercial including the Provincial districts of Arauco boundaries of the city of Temuco for and of Biobío in the VIII Region, and of agricultural supply purchasing, and the Provincial districts of Valdivia in the X establishing the factors that explain its Region. The cities of Los Angeles, Temuco development. and Valdivia were excluded as study units. 180 CIENCIA E INVESTIGACION AGRARIA

destination j; cij was a variable of spatial For the empirical delimitation of commercial separation from origin i at destination j; k areas in a regional or national environment, was the gravitational constant; á1, á2 and á3 customarily qualified informants were were the parameters of the model. surveyed (De Juan, 1998; Casares and Rebollo, 2000). Therefore, a personal survey Given that the model was multiplicative was given to the Planning and Coordination potential, it was calculated previously Communal Secretaries (SECPLAC) of the through logarithmic transformations, districts previously mentioned. considering the following functional form:

The SECPLACs were chosen in (3) consideration to the knowledge that they can have of the district reality on The commercial flows constituted to those demographic, social and economic aspects determined by the survey to SECPLACs. and familiarity with the general purchasing Distance and later travel time was used as habits of the residents of their districts. restrictive variable of commercial flow. As Furthermore, they were told previously that a measurement of commercial attraction they could request others neighbors of the three variables were used successively, the same district to complete and/or improve population of the district of origin and the information required. destination based on the information provided by the 2002 Census (INE, 2003), The survey was performed using a the number of commercial patents of questionnaire that identified the percentage agricultural supplies stores, and their of expenditure in agricultural supplies made corresponding commercial area. Thus, four within the district of residence and the different conditions of the model were proportion of this purchase made outside calculated as follows: the residential district. Additionally, it was requested to indicate the two most important (4) districts for shopping outside their own district and to point out the percentage of (5) disbursement made in each one. The SECPLACs were interviewed between (6) October 2002 and April 2003. (7) The unrestricted model of spatial interaction (Fotheringham and O’Kelly, 1989; equation Pi was the population of origin i; Pj was the 2) was used to determine the factors that population of destination j; Li was the explain the commercial flow of agricultural number of commercial licenses of origin i; supplies between Districts of the VIII, IX Lj was the number of commercial licenses and X Region and the composition of the of destination j; Si was the commercial 2 commercial area of Temuco. surface (m ) of origin i; Sj was the 2 commercial area (m ) of destination j; dij (2) was the distance (km) from origin i to destination j; tij was travel time (minutes) where Fij were the flows between origin i from origin i to destination j. and destination j; Vi were the characteristics of origin i; Wj were the characteristics of In the model, the two first specifications VOL 32 N°3 SEPTEMBER - DECEMBER 2005. 181 were determined for all the districts that the results of the commercial flows of 50 responded through SECPLACs. For the two districts of the VIII, IX and X Region of last conditions, only those belonging to the Chile, representing 83% of responses. commercial area of Temuco were considered, Temuco’s commercial area of attraction or those that circumvent expenses towards included 35 districts, one district from this city for the provision of agricultural , all districts of the IX supplies. The two last specifications were Region and 4 districts of Valdivia estimated using travel time, because better Province. adjustment was achieved with this restrictive variable. Calculation of the model consisted The mean proportion of agricultural supply in finding the coefficients of the equation purchases within the district where the through the multiple regression technique, farm was located reached 37%, the using as calculation method the ordinary remaining 63% went to other districts, mean squares of the SPSS 11.0 (SPSS.Inc., being Temuco the main destination of USA) statistical program. expenses. The escaped flows fluctuated between 10 and 100%. Eight districts The list of commercial patents of each gravitated commercially above Temuco. district that constitute the commercial area These were the districts of Cunco, Lautaro, of Temuco was requested directly from each Nueva Imperial, Padre Las Casas, Vilcún, municipality. To calculate the commercial Villarica,Traiguén and Victoria. The area related to agricultural supply sales escaped flows varied between 20 and 90%. establishments, a personal survey was made Within of this group of districts, Villarrica, of a representative sample of business Traiguén and Victoria were far from the owners (6 establishments in the district of regional capital. Temuco and 27 businesses belonging to the districts of the commercial area of Temuco, Temuco was the first choice of shopping of a universe of 36 and 76 patents, for farmers that purchased their supplies respectively). For this purpose a outside their district of origin. These questionnaire was used that inquired about districts were Carahue, Freire, Galvarino, the total area and the area assigned to sales Gorbea, Loncoche, Melipeuco, Perquenco, in each establishment. The sample was Pitrufquén, Pucón, Teodoro Schmidt, obtained using the statistical formula by Curacautín, Ercilla, Purén, Mariquina, Scheaffer et al. (1996), referred to the and Tirúa with flow stratified random sample, dichotomy circumvention towards Temuco that variable, with 95% confidence and 5% fluctuated between 5 and 85%. estimated error with 0.5 p and q. The surveys were performed between July 2003 and Secondary procurement destinations were February 2004. The total area and sales area the city of Villarrica that attracted corresponding to the universe of patents of commercial flows from Loncoche, each district, was obtained multiplying the Pitrufquén and Pucón. The city of Victoria means of surveys performed according to exerted attraction on Curacautín and Ercilla. the sample and the total patents in each case. Similarly, Pitrufquén generated travel from Freire and Gorbea. The city of Valdivia in RESULTS the X Region, attracted buyers from Mariquina and Panguipulli, these last two Temuco’s commercial agricultural supply districts constituted a shared gravitational provisioning area. Table 1 and 2 show zone of commercial areas. 182 CIENCIA E INVESTIGACION AGRARIA

Table 1. Commercial flows of agricultural external inputs determined for the districts of the VIII, IX and X Regions of Chile in 2002-2003. Purchase, % Selected districts Districts Inside1 Outside1 First district2 % Second district2 % Carahue 70 30 Temuco 21 Imperial 9 Cunco 10 90 Temuco 90 Curarrehue 0 100 Pucón 100 Freire 1 99 Temuco 70 Pitrufquén 29 Galvarino 20 80 Temuco 60 Traiguén 20 Gorbea 30 70 Temuco 50 Pitrufquén 20 Lautaro 70 30 Temuco 30 Loncoche 10 90 Temuco 70 Villarrica 20 Melipeuco 30 70 Temuco 50 Cunco 20 Nueva Imperial 70 30 Temuco 30 Padre Las Casas 30 70 Temuco 70 Perquenco 30 70 Temuco 65 Lautaro 5 Pitrufquén 60 40 Temuco 30 Villarrica 10 Pucón 5 95 Temuco 85 Villarrica 10 Puerto Saavedra 80 20 Carahue 20Ê Teodoro Schmidt 90 10 Temuco 5 Toltén 5 Toltén 50 50 Teodoro Schmidt 30 Temuco 20 Vilcún 50 50 Temuco 50 Villarrica 80 20 Temuco 20 Angol 40 60 Los Angeles 30 Temuco 30 Collipulli 70 30 Los Angeles 20 Temuco 10 Curacautín 60 40 Temuco 38 Victoria 2 Ercilla 0 100 Temuco 50 Victoria 50 Lonquimay 80 20 Curacautín 16 Temuco 4 Los Sauces 10 90 Angol 70 Temuco 20 0 100 Traiguén 50 Temuco 50 Purén 50 50 Temuco 35 Angol 15 Renaico 0 100 Los Angeles 70 Angol 30 Traiguén 20 80 Temuco 80 Victoria 60 40 Temuco 40 Corral 5 95 Valdivia 57 Temuco 38 Lanco 40 60 Valdivia 40 Temuco 20 Mariquina 50 50 Temuco 40 Valdivia 10 Panguipulli 30 70 Temuco 42 Valdivia 28 Tirúa 10 90 Temuco 63 Concepción 27 1Purchased made inside or outside of the district where farms were located. 2First and second districts preferred to purchase agricultural supplies outside of the district where the farm is located. VOL 32 N°3 SEPTEMBER - DECEMBER 2005. 183

Table 2. Districts in the VIII y X Region of Chile that were not attracted commercially by Temuco. Purchase, % Selected districts Districts Inside1 Outside1 First district2 % Second districts2 % Los Alamos 0 100 Cañete 60 Concepción 40 Cañete 80 20 Los Álamos 16 Concepción 4 30 70 Cañete 49 Concepción 21 5 95 Concepción 67 Arauco 28 Laja 10 90 Los Angeles 81 Concepción 9 Nacimiento 10 90 Los Angeles 85 Concepción 5 0 100 Los Angeles 80 Nacimiento 20 10 90 Los Angeles 75 Concepción 15 0 100 Los Angeles 70 Laja 30 Santa Bárbara 20 80 Los Angeles 80 50 50 Los Angeles 32 Chillán 18 50 50 Valdivia 45 5 La Unión 40 60 Osorno 60 Máfil 70 30 Valdivia 30 1Purchased made inside or outside of the district where farms were located. 2First and second districts preferred to purchase agricultural supplies outside of the district where the farm is located.

Other districts that attracted expense flows Schmidt from Toltén, existing between secondarily were Nueva Imperial from these districts flows back and forth. The Carahue, Traiguén from Galvarino, Cunco flows of expenses attracted by Temuco from Melipeuco, Lautaro from Perquenco, fluctuated between 4 and 50%. Three Toltén from Teodoro Schmidt, Angol from districts gravitated indirectly on Temuco, Purén and Concepción from Tirúa. The Puerto Saavedra attracted by Carahue, latest district was a gravitational area shared Curarrehue attracted by Pucón and, Renaico by different districts. The extent of the that diverted flows primarily towards Los flows attracted by the secondary Angeles and secondarily to Angol, creating procurement destination fluctuated between a shared gravitational zone. 2 and 50%. The districts of Los Alamos, Cañete, Eight districts gravitated secondarily but Contulmo and Curanilahue in the Province directly on Temuco. Main destinations of Arauco, the districts of Laja, Nacimiento, were Los Angeles and Valdivia in the VIII Negrete, Quilaco, San Rosendo, Santa and X Region, respectively. Los Angeles Bárbara and Yumbel in Biobío Province primarily attracted buyers from Angol and and the districts of Futrono, La Unión and Collipulli, Valdivia exerted attraction on Lago Ranco in the Province of Valdivia, Lanco and Corral. These four districts were did not gravitate commercially on Temuco shared gravitational zones of commercial for the procurement of agricultural supplies disbursement outside the IX Region, the (Table 2). In this case, the districts of the first two and of returns the last ones. Province of Arauco re-routed on average Curacautín attracted commercial flows 71.3% of the commercial expenses from Lonquimay, Angol from Los Sauces, primarily towards Cañete, Concepción, Los Traiguén from Lumaco and Teodoro Alamos and Arauco. 184 CIENCIA E INVESTIGACION AGRARIA

The greatest expense circumvention was The districts of Carahue, Lautaro, Puerto from the districts of Biobío Province, Saavedra, Toltén, Collipulli, Lonquimay 85.7% with destination towards Los and Victoria showed a highly efficient use Angeles in all cases as first choice and, of commercial space, since they manage to secondarily, towards Concepción, retain an important proportion of expenses Nacimiento, Laja and Chillán, located in in agricultural supplies with low sales areas. the Province of Ñuble, in the case of The situation of the districts of Melipeuco, Yumbel. The lowest diversion of expenses Pucón, Vilcún, Los Sauces and Purén that was from the districts of registered purchases from the district where that had an average of 60% circumvention the property was located without having a towards the cities of Valdivia, Osorno, Río commercial area for supply sales, indicates Bueno and Paillaco. the possible presence of informal commerce or lack of knowledge regarding the Table 3 shows the number of patents and procurement patterns. commercial area of sales establishments of agricultural products in the districts of the Modeling of the commercial flows of commercial area of Temuco. The city of agricultural supplies. The coefficients of Temuco had the largest number of the population variables and number of commercial patents. Considering the sales commercial patents used to measure the area, Temuco ranked third after Freire and commercial attraction of the districts of Curacautín, with a proportion close that of origin on the expense flows were negative Angol and Traiguén. These results, as (Table 4). The coefficients for population, expected, reflect that in this type of products number of commercial patents and sales area the commercial area does not directly of the districts of destination of flows were increase with the potential level of current positive, whereas both restriction variables demand, estimated by the number of had negative coefficients. The coefficients inhabitants. In a high proportion of districts, of the three variables were statistically there was a high proportion of the total area significant (p < 0.05) in the specification of allocated to storage, related to the volume the gravitational model that uses population of commercialized products. Twenty-seven as an attribute of the district of origin, percent of the districts lacked this type of destination of the commercial flows and commerce. travel time as restriction variables. The global adjustment of the model improved when To certain extent, some of these results other variables that reflected the commercial reflect how efficient commercial space is attraction of the procurement centers were used. For instance, in the district of Freire introduced, i.e. number of business patents the largest proportion of expenses in of agricultural supply stores and the related agricultural supplies was diverted towards commercial area, showing determination Temuco and Pitrufquén, despite having the coefficients higher than 40%, considered largest commercial surface of the area. This acceptable in this type of research (Medina, would indicate the inefficient use of 1997). Not withstanding, the variable referred commercial space or the development of a to the district of origin of the expense re- commercial mix not congruent with routing had statistically non-significant consumer needs. The districts of Cunco, coefficients (p>0.05) and were positive for Curarrehue, Angol and Traiguén would be the commercial area. This contrasts the theory in a similar inefficient situation. of commercial attraction. VOL 32 N°3 SEPTEMBER - DECEMBER 2005. 185

Table 3. Licenses and commercial space for selling agricultural products corresponding to the districts that make up Temuco’s trade area, IX Region, Chile. Districts Commercial Commercial Proportion of the Proportion of the total licenses area total store area floor of the trade area (m2) (%) (%) Province of Arauco, VIII Region 37º5’-38º South latitude Cañete 5 80 6.9 0.7 Contulmo 0 0 0 0 Tirúa 0 0 0 0 Province of Malleco, IX Region 37º5’-38º5’ South latitude Angol 4 1,200 46.2 6.4 Collipulli 1 60.0 100 0.5 Curacautín 3 1,500 100 12.6 Ercilla 0 0 0 0 Lonquimay 2 40.0 100 0.3 Los Sauces 0 0 0 0 Lumaco 0 0 0 0 Purén 0 0 0 0 Renaico 0 0 0 0 Traiguén 5 720 100 6.1 Victoria 1 27 19.0 0.2 Province of Cautín, IX Region 38º5’-39º5’ South latitude Temuco 36 893 14.0 7.5 Carahue 3 75 55.6 0.6 Cunco 3 450 100 3.8 Curarrehue 3 108 100 0.9 Freire 1 4,200 100 35.3 Galvarino 2 200 100 1.7 Gorbea 2 40 25.0 0.3 Lautaro 2 66 6.5 0.6 Loncoche 3 63 8.5 0.5 Melipeuco 0 0 0 0 Nueva Imperial 1 360 60.0 3.0 Padre Las Casas 5 45 1.5 0.4 Perquenco 1 42 45.7 0.4 Pitrufquén 4 476 3.2 4.0 Pucón 0 0 0 0 Puerto Saavedra 1 60 75.0 0.5 Teodoro Schmidt 5 500 100 4.2 Toltén 2 50 100 0.4 Vilcún 1 0 0 0 Villarrica 7 112 2.4 0.9 Province of Valdivia, X Region 39º5’ South latitude Lanco 5 280 43.8 2.4 Mariquina 2 108 15.3 0.9 Panguipulli 2 144 16.0 1.2 186 CIENCIA E INVESTIGACION AGRARIA

DISCUSION AND CONCLUSIONS border of the IX Region, whose inhabitants also travel to Valdivia to buy; 2. Districts Because to travel long distances to procure located north of the IX Region that travel supplies have a direct incremental effect to Los Angeles to buy 3. A district of on the production costs, a low incidence of Arauco Province that commercially also inter-communal procurement travel and a depends on the city of Concepción. This small commercial area around Temuco situation, together with the large commercial would be expected in this studied. However, area around Temuco, account for the strong the presence of commercial flows that commercial competition existing between circumvented the district where the agricultural supply businesspersons and agricultural property was located probably distributors, that was reflected both in prices was enhanced by marketing strategies of and sales associated services. distributors of agricultural supplies in the region. Mainly those with headquarters in The districts of Angol, Villarrica and Victoria Temuco, that offered a broad range of free created three commercial sub areas within services linked to the purchase (soil analysis, the commercial area of Temuco. These advice on how to apply agro-chemicals, farmers purchased in a main location of a professional visits, special containers). sub area that in turn gravitates around the Additionally, they provided free delivery main attraction pole of the area. The main over a certain amount. attraction pole of sub areas had equipment and sufficient commercial attraction capacity Within the commercial area of Temuco to create around it a zone of influence from there was three shared gravitational zones: which to attract an important part of its 1. Four districts of the X Region in the expense flows (Casares and Rebollo, 2000).

Table 4. Determination of the commercial gravitation model of agricultural raw materials using different variables of attraction and restriction in Southern Chile Variables of R2 Lk β1 β2 β3 F-Snedecor commercial attraction (%)

Población/distancia 2.662 -0.276 0.368 * -0.232 * 13.7 4.330 * (1.724) (-1.915) (3.432) (-2.184)

Population/travel 3.023 -0.318 * 0.427 * -0.398 * 15.6 5.046 * time (1.968) (-2.188) (3.738) (-2.595)

Commercial 3.304 * -0.096 0.532 * -0.414 * 41.8 8.847 * licenses/travel time (6.548) (-0.497) (5.096) (-2.783)

Commercial 0.399 0.02988 0.632 * -0.368 * 45.2 9.911 * floor/travel time (0.431) (0.368) (5.413) (-2.407)

The Lk value designates the natural logarithm of the variable k. and the values β1, β2 y β3 the coefficients of the variables of each specification. Numbers between parenthesis correspond to the value of the t student. *: statistically significant (p < 0.05). VOL 32 N°3 SEPTEMBER - DECEMBER 2005. 187

The coefficients that resulted from the of the provinces of Arauco and Valdivia in estimate of the commercial gravitation the VIII and X Region, respectively. The model coincided with those of Medina districts of Angol, Villarrica and Victoria (1997) for Spain. The coefficients with were attraction pole of commercial sub negative sign for the size of the district of areas attracting part of the expenses origin variable demonstrated an inverse circumvented from neighboring districts. relation between it and the circumvented flow of expense. This would imply that the Regarding the southern zone of Chile, it size of the district acted as a restrictive was possible to validate the gravitational factor in the flows of commercial model of agricultural supplies using the expenditure. The coefficients of the size of population of the districts of origin and the district of destination variable with destination of expense flows, and travel positive sign indicate that the larger the time as explanatory variables of commercial supply of the district of commercial flows. The model’s adjustment destination, the greater was the flow of improved by using the number of business expenditure exchanged with the district of patents and the commercial area as origin. The coefficients of the distance and variables that reflect the commercial travel time variable with negative sign attraction exerted by a procurement center would indicate that the distance or travel on its environment. time towards the larger interurban procurement centers, acted as a flow- Travel, to buy agricultural supplies outside restricting factor. the district where the property was located, was made choosing interurban procurement The three variables were statistically centers that offered the largest variety of significant only in the specification of the products, and the best business conditions model that uses population and travel time and services to farmers. as explanatory variables of the phenomenon of commercial attraction. However, the RESUMEN territorial distribution of the commercial availability of agricultural supplies was Para evaluar la existencia de flujos de very relevant in explaining interurban travel compra de insumos agrícolas atraídos por to purchase these products. This was Temuco y delimitar su área comercial, se noticeably concentrated in certain places encuestó a los Secretarios Comunales de and scarce or nonexistent in others. Planificación de las comunas de la IX According to these results, farmers were Región y de las provincias de Arauco, willing to acquire the supplies required for Biobío y Valdivia, definidas como unidades production in procurement centers far from de estudio por el modelo gravitacional their property because the market offers determinista de delimitación de áreas better commercial conditions reflected in comerciales. Temuco, como cabecera lower transaction costs. comercial del área, atrajo flujos de gasto de todas las comunas de la IX Región y de Therefore, Temuco as an attraction pole of comunas limítrofes de la VIII y X Región the commercial area of this zone attracted de Chile, totalizando 35 comunas atraídas directly or indirectly commercial flows for comercialmente. Se observaron zonas de agricultural supplies from all the districts gravitación compartida con las áreas of the IX Region. Indirectly, it attracted comerciales de las ciudades de Valdivia, commercial flow from neighboring districts Concepción y Los Angeles. Mediante la 188 CIENCIA E INVESTIGACION AGRARIA estimación del modelo de gravitación De Juan, M. D. 1998. La atracción que comercial tradicional, se determinó que los ejercen los centros comerciales sobre desplazamientos de compra fuera de la los consumidores, Servicio de comuna de ubicación del predio para las Publicaciones de la Universidad de adquisiciones de insumos agrícolas, se Alicante. Murcia, España. 139 pp. realizaron seleccionando los centros de Fotheringham, A.S., and M.E. O’Kelly. compra interurbanos de mayor oferta 1989. Spatial Interaction Models: comercial, que ofrecen mejores condiciones Formulation and Applications. Kluwer comerciales y de servicios a los productores Academic Publishers, Dordrect, The agrícolas, actuando la distancia o el tiempo Netherlands. 221 pp. de desplazamiento como factores de Gil, I.A., A. Mollá y G. Berenguer. 1997. restricción a los desplazamientos de compra. La imagen del punto de venta y su incidencia sobre la selección del Palabras clave: flujos comerciales, establecimiento. AEDEMO 54: 46-54. gravitación comercial, insumos agrícolas. Huff, D.L. 1964. Defining and estimating a trading area. Journal of Marketing ACKNOWLEDGEMENTS 28: 34-38. INE. 2003. Censo 2002. Resultados The author wants to thank FORD Foundation Volumen I: Población; País – Región. for contributions made through the TEFE Instituto Nacional de Estadística. Project 150204 of the Research and Gobierno de Chile, Santiago, Chile. Development Department and The Local 356 pp. and Regional Development Institute of the LaForge, R., R. Reese, and W. Stanton. 1984. Universidad de la Frontera, Temuco, Chile. Identifying and attracting consumer outshoppers. Journal of Small Business REFERENCES Management 23: 22-29. Lösch, A. 1954. The Economics of Banco Central de Chile. 2003. Producto Location, Traducido por W. H. Woglam Interno Bruto Regional 1996-2000. y F. Stolper en 1954, Yale University Base 1996. Press, New Haven. 156 pp. http://www.bcentral.cl/esp/estpub/pu Más, F. 1996. La imagen de los centros blicaciones/cuentasnacionales/cuenta comerciales suburbanos en el modelo s07.htm de Huff: una aplicación empírica. Libro Casares, J. y A. Rebollo. 2000. Distribución de ponencias de AEDEM, Granada, Comercial, Editorial Civitas, Madrid, España. p. 165-178. España. 267 pp. Mayo, E.J., L. Jarvis, and J.A. Xander. Converse, D. 1949. New laws of retail 1988. Beyond the gravity model. gravitation. Journal of Marketing 14: Journal of the Academy of Marketing 379-384. Science 16: 23-29. Craig, C.S., A. Ghosh, and S. McLafferty. Medina, O. 1997. El Proceso de Selección 1984. Models of the retail location de Centros de Compra Interurbanos por process: A review. Journal of Retailing el Consumidor Español. Tesis doctoral. 60: 5-36. Universidad Autónoma de Madrid. Christaller, W. 1933. Central Places in Madrid, España. 373 pp. Southern Germany, Traducido por C. Nakanishi, M.L., and G. Cooper. 1974. W. Baskin, Prentice Hall, Nueva Jersey, Parameter estimation for a USA. 1966. 320 pp. multiplicative competitive interaction VOL 32 N°3 SEPTEMBER - DECEMBER 2005. 189

model. Least squares approach. Journal Gravitation, W. J. Reilly Inc., Nueva of Marketing Research 11: 303-311. York. 321 pp. O’Kelly, M.E. 1999. Trade-area models and Scheaffer, R., W. Mendwenhall y L. Ott. choice-based samples. Environment and 1996. Elementos de Muestreo. Grupo Planning A 1: 613-627. Editorial Iberoamericana S.A. Primera Reilly, W.J. 1931. The Law Retail edición. México. 321pp.