This problem has been addressed in the research literature based on the assumption that the exact risk aversion coefficients of the sales agents are known to the firm, which may not be true in most applications.
For example, in Hogan et al. [ 18], the correlation coefficient between electrolyte sales and hospital diagnoses of respiratory and diarrheal illness was 0.90 (95% CI, 0.87 0.93) when drug sales were assumed to precede clinical diagnosis data by 1.7 weeks.
The predictions of ILI incidence from drug sales were evaluated by Spearman correlation coefficients.
In comparing the variable "sales growth" in two periods, the coefficient of correlation, r, falls in the range of 1.00 to –1.00.
Table 7 Bootstrapped regression results Dependent variable = total peak demand Regression 1 Regression 2 Variables Coefficient z value Coefficient z value Exports (log) 0.08*** 4.15 0.08*** 4.00 Sales to Umeme (log) 0.35*** 3.66 Peak Sales Umeme (log) 0.13 0.95 Off-Peak Sales Umeme (log) 0.28 1.14 Shoulder Sales Umeme (log) 0.03 0.15 Sales to other dist.
Given enough historical data to calculate a coefficient of price elasticity, the sales effect of price cutting can be quantified, though with a good deal of trouble.
Not all of the regressions for the occupations found statistically significant temperature coefficients, but with the exception of Sales Workers, all had negative coefficients.Of the eight different occupations, four were significant at the one percent level and one was significant at the five percent level.
In the same regression, the coefficients of UETCL energy exports and sales to other distributors have the same magnitude, impact, and statistical significance on peak demand as that in regression 1.
Meanwhile, inflation-adjusted disposable personal income and precipitation also have a positive association with new motorcycle sales, while temperature has a negative association; however, these coefficients were not statistically significant.
The figures above show the coefficient of correlation for EPS growth and sales growth for more than 300 large nonfinancial companies in the United States.
