5.1. Telecommunication Usage
Equation (7) is adapted to the data described in the previous section. The dependent flow variable is, for each of the 11 economic sectors, the total conversation seconds to regular destinations (MTS + WATS). Thus, 11 equations are estimated. The labor input is the total sectoral employment in each exchange, and the telecommunication price is the average price (Equation (10)). There are no data on the prices of the sectoral outputs and the other inputs (materials, energy, capital, land, etc.) across the exchanges of the LATA. While some prices (e.g., capital) are unlikely to vary within the LATA, other prices may vary, and these variations may be captured by proxy variables, such as the distance between the exchange and the economic core of the LATA, or the urban/rural character of the exchange. Let
LOC be a vector representing these locational variables. The general form of the telephone flow function is then:
Two infrastructure variables (vector T) turned out to have significant effects on the flows:
Digital switching is illustrative of advanced telephone technologies, as it makes available touch-tone (a prerequisite for various business services, such as telephone banking, reservations, and voice messaging) and custom-calling services (e.g., three-way calling, call forwarding, call waiting, and caller identification), and reduces the amount of dedicated loop plant by allowing wireless connections to remote nodes. Close to 60% of the exchanges had digital switching in 1990. Several locational variables (vector LOC) were considered, and the following ones turned out to be significant in some or all the estimated equations:
RUR = ratio of rural to total population, measuring the rural character of the exchange;
DIST = distance (in miles) between the central office and the population-weighted center of gravity of the LATA, measuring the peripheral character of the exchange; it may have either a positive impact (need to increase communications to compensate for isolation) or a negative one (isolation decreases the need to communicate);
LOQ = employment-based location quotient (1990), reflecting the relationship between export activities and telecommunications.
RUR varies between 0 and 1, with an average value of 0.84; 75% of the exchanges have RUR > 0.8, and 72% are completely rural. There is only one exchange that is completely urban (RUR = 0), and 16% have RUR < 0.25. DIST varies between 2.4 and 132 miles, with an average of 42.5 miles. Equation (11) can then be rewritten as:
Various functional specifications of Equation (12) have been considered. The first specification, where the elasticities of L and PMST are assumed constant and independent of the other variables, turned out to be inferior in explanatory power to the second specification, where the employment elasticity is a function of the infrastructure (ISW and WAL) and locational (RUR, LOQ, and DIST) variables. The price elasticity turned out to be unrelated to these variables. The final functional form is then
In order to test for interactions between the rural character of the exchange (RUR) and its telecommunications infrastructure (ISW and WAL), the products of these variables were included in the elasticity function b, in addition to all the variables taken separately. After deleting the insignificant variables, the final specification of b is:
All regression models are estimated using ordinary least squares. The regression results and the employment elasticities under different locational and technological scenarios, are presented in
Table 5 and
Table 6. The price elasticities are all highly significant (1% level), negative, and consistent with earlier estimates [
20]. The analysis of the employment elasticities is more complicated. First, consider the coefficient of lnL, which is positive and highly significant in all cases, and varying within the range [0.7–1.0]. This coefficient would be the actual employment elasticity if the exchange were completely urban (RUR = 0), located exactly at the regional core (DIST = 0), and with a location quotient equal to zero. This is unfeasible, as LOC = 0 implies no employment in the sector. Alternatively, and as a benchmark, consider a fully urban exchange located 10 miles away from the regional core, and with a location quotient of 1. The corresponding elasticities, reported as Case 1 in
Table 6, vary between 0.553 and 0.951. The positive sign points to the complementarity between telecommunications and labor inputs, i.e., the more employees the more conversation seconds. This result casts doubts on the hypothesis that the efficiencies derived from increased use of ICTs allow for a reduction in the labor input. This complementarity is particularly strong in Sectors 9 (0.951: Professional services), 6 (0.893: FIRE), and 11 (0.933: Agriculture and mining). The lower elasticity for Sector 7 (0.553: Business and repair services) is puzzling but may be due to a predominance of repair services, which may require less telecommunication interactions per employee. Next, consider how the previous results are modified in a rural environment (RUR = 1), in the absence of advanced telecommunications infrastructure (ISW = 0 and WAL = 0). The coefficients of RUR*lnL are all negative, and, except for Sectors 10 (public administration) and 11 (agriculture and mining), significant at least at the 5% level, pointing to an important “rural penalty“, i.e., there is less complementarity between labor and telecommunications in rural areas, and thus less calling per employee. The corresponding elasticities are presented as Case 2 in
Table 6. In the case of Sectors 3, 4, 7, and 8, the elasticities are in the range [0.23–0.33], thus much closer to the pure substitution case (negative elasticity).
However, the “rural penalty” is reduced by the availability of advanced telecommunication infrastructure, as indicated by the positive signs of the variables RUR*ISW*lnE and RUR*WAL*lnE. The impact of having digital switching is significant (10% at least) in seven sectors (1–4, 6, 8, and 9), while the impact of having WATS access lines is significant in all sectors. Employment elasticities have been computed for two “rural” scenarios, reported as Cases 3 and 4 in
Table 6: (1) digital switching, but no WATS lines, and (2) digital switching with 10 WATS lines. Consider the case of Sector 3 (TCPU). Without advanced features, the employment elasticity is 0.335. With a digital switch, this elasticity increases to 0.504, and, with 10 WATS lines, to 1.034. Similar results apply to the other sectors, more or less dramatically. Clearly, an advanced telecommunications infrastructure leads to a more intensive use of telecommunications (i.e., telephone flows) in rural areas. Interestingly, when the variables ISW and WAL were introduced into the model separately from the RUR variable, they turned out to be much less significant, which suggests a distinct interaction between a rural environment and advanced telecommunications infrastructure (TI) in generating telecommunications flows. This increased usage may be due to specific subgroups of firms that locate in rural areas to take advantage of the TI.
The impact of the core-periphery location of an exchange, as measured by the coefficient of the variable DIST*lnE, is positive and significant (5%) for five sectors (3, 5–7, and 9). This result suggests that the farther away the exchange is located from the regional economic core, the more isolated this exchange is, and therefore the higher the level of telecommunications interactions needed, as they replace face-to-face interactions that are more common in urban, higher-density areas. Elasticities have been computed for a rural exchange with advanced features located 100 miles away from the regional core, and are reported as Case 5 in
Table 6. Consider again Sector 3 (TCPU): Increasing the distance from 10 to 100 miles increases the employment elasticity from 1.034 to 1.289. Finally, the impact of the exchange location quotient, as measured by the coefficient of the variable LOQ*lnE, is negative and highly significant (1%) for only five sectors (2, 7, 8, 10, and 11), and insignificant (though mostly negative) in all the other cases. These results are counterintuitive, as the expectation is that the higher LOQ, the larger the exports out of the exchange, and therefore the higher the level of telecommunications interactions between the exchange and other export-destination exchanges. However, it may be that some activities with a high LOQ do export much of their goods beyond the LATA’s boundaries, and these exports require inter-LATA telecommunications interactions not reflected in the available database. This is quite likely the case for primary and secondary activities, such as manufacturing (Sector 2) and agriculture and mining (Sector 11). The three other sectors with significant coefficients are all consumer-oriented: Repair services (Sector 7), personal services (Sector 8), and public administration (Sector 10). It may be that high concentrations of such activities constitute attracting poles, where consumers come to purchase or receive the services. They possibly initiate prior interactions, thus reducing the telecommunications needs of these activities. Elasticities have been computed under Case 6 in
Table 6, modifying Case 5 by increasing the location quotient from one to two. Except for Sector 5, all elasticities slightly decline, remaining within the range [0.72–1.53].
5.2. Telecommunications Infrastructure Provision
It is assumed that the LEC’s optimization process presented in
Section 3.2 applies to each exchange within the LEC’s service territory. The same wage rate applies to all employees of the LEC, whatever the exchange they are working in. Hence, P
L does not vary across exchanges, and its effect is unobservable. Equation (9) is thus reduced to:
The focus is on digital switching provision, and the dependent variable is taken as the binary variable ISW, equal to 1 if digital switching is installed in the exchange in 1990, and to 0 if not. Such switches have been installed throughout the 1980–1990 decade, with very few available in 1980. The installation decision may be a function of past observed flows, of future predicted flows, or of both types of flows. Because flow data are only available in 1990, the employments in the 11 sectors in 1980 and 1990 are used as proxies for these flows and are defined as the “Market Variables”. The infrastructure cost variables are proxied by a set of “Locational Variables”. Equation (15) is transformed into a logit model, with:
Neither the 1990 employment nor the 1980–1990 employment increment variables turned out to be significant. Location quotients and occupation-related employment variables were also considered for both years, but with insignificant results. However, several of the 1980 employment variables (construction, TCPU, retail, business and repair services, and professional services) turned out to be highly significant. Among the locational variables, only DIST, the distance of the exchange to the regional core, and POPCITY, the population of all the cities within the exchange boundaries, turned out to be significant. POPCITY varies between 0 and 99,288, with a mean of 2607. While city population represents 35% of the LATA’s population, there are only 16 exchanges with a city, in part or in whole. The results of the logit estimation are presented in
Table 7.
The significance of the 1980 employment variables suggests that digital switching installation decisions are based on past observed market demands. Construction, retail, and professional services activities increase the probability of digital switching, and must be viewed by the LEC as likely users of the services made possible by such switches, potentially increasing the profitability of these services. In contrast, TCPU and business/repair services activities have a negative effect, possibly because they are viewed as less likely users of these services. The larger the population of a city located within the exchange, the higher the probability of digital switching, probably because the LEC views such population as more likely to use digital services and making these services profitable. Finally, the farther away from the regional core, the lower the probability of digital switching. This probably reflects a strategy of installing digital switches first close to the core and within metropolitan areas, and then moving outwards, towards less populated, more rural exchanges. As for the provision of other rural services, distance and low population density appear to be barriers to the deployment of advanced telecommunications technologies. Finally, one should recognize the possible endogeneity between infrastructure provision and market demands, namely that market demands may also be a function of past infrastructure provision, and not only the other way around. Unfortunately, the available data preclude the testing of this hypothesis, as detailed data on switching technology prior to 1990 cannot be obtained.