Analysis of Spearman and Pearson correlation between NPS and selected growth and profit variables
| Variable | Pearson correlation coefficient | Spearman correlation coefficient | ||
|---|---|---|---|---|
| GRS | 0.16752526 | –0.043691115 | ||
| GRE | 0.155635068 | 0.150436919 | ||
| GRNR | 0.088937199 | 0.025886473 | ||
| ROA | 0.325424301 | * | 0.316394781 | * |
| ROAE | 0.206332032 | 0.139961991 | ||
| ROS | 0.152675197 | 0.249374388 | * | |
| ROSE | 0.186006935 | 0.047260248 | ||
| ROE | 0.181569744 | 0.364680642 | * | |
| ROEE | 0.230083687 | * | 0.26248856 | * |
Regression analysis of profitability and NPS
| ROA | ROAE | ROE | ROEE | ROS | ROSE | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| NPS | Const | NPS | Const | NPS | Const | NPS | Const | NPS | Const | NPS | Const | |
| Coefficient | 0.001591 | 0.014096 | 0.000962 | 0.102123 | 0.003727 | 0.096028 | 0.007466 | 0.322086 | 0.001243 | 0.004102 | 0.000473 | 0.049916 |
| Std. error | 0.000537 | 0.032101 | 0.00053 | 0.03166 | 0.002346 | 0.140126 | 0.003671 | 0.219243 | 0.000936 | 0.055881 | 0.00029 | 0.017347 |
| t-ratio | 2.9606 | 0.4391 | 1.814 | 3.2256 | 1.5883 | 0.6853 | 2.0338 | 1.4691 | 1.3289 | 0.0734 | 1.6285 | 2.8775 |
| value | 0.00412 | 0.66187 | 0.07374 | 0.00187 | 0.11648 | 0.4953 | 0.04556 | 0.14605 | 0.18795 | 0.94168 | 0.10767 | 0.00524 |
| *** | * | *** | ** | *** | ||||||||
| Mean dependent variable | 0.100638 | 0.154419 | 0.298698 | 0.728128 | 0.071727 | 0.07564 | ||||||
Standard dev. dependent var. | 0.121494 | 0.115793 | 0.509944 | 0.806234 | 0.202355 | 0.063182 | ||||||
| Sum squared residuals | 0.989825 | 0.962795 | 18.86027 | 46.17018 | 2.999467 | 0.289043 | ||||||
| E. of regression | 0.115655 | 0.114065 | 0.504845 | 0.789887 | 0.201329 | 0.062498 | ||||||
| R2 | 0.105901 | 0.042573 | 0.032968 | 0.052939 | 0.02331 | 0.034599 | ||||||
| Adjusted R2 | 0.093819 | 0.029635 | 0.0199 | 0.04014 | 0.010111 | 0.021553 | ||||||
| F(1,74) | 8.764882 | 3.29048 | 2.52277 | 4.136425 | 1.766086 | 2.652052 | ||||||
| p-value (F) | 0.004124 | 0.073736 | 0.116477 | 0.045555 | 0.18795 | 0.107667 | ||||||
Variables used in the study
| Variable | Acronym | Description |
|---|---|---|
| Net promoter score | NPS | The difference in the proportions of respondents ranked as promoters and detractors. The variable ranges between –100 and 100. |
| Growth of sales | GRS | The difference in sales between this year and previous year divided by the previous year’s sales |
| Growth of EBITDA | GRE | The difference between this year’s earnings before interests, tax, depreciation, and amortization (EBITDA) and previous year’s EBITDA divided by previous year’s EBITDA |
| Growth of net result | GRNR | The difference between the net result and previous year’s net result divided by previous year’s net result |
| Return on assets | ROA | Ratio of the net result to the total of assets |
| Return on assets 2 | ROAE | Ratio of the EBITDA to the total of assets |
| Return on sales | ROS | Ratio of the net result to the total of sales |
| Return on sales 2 | ROSE | Ratio of the EBITDA to the total of sales |
| Return on equity | ROE | Ratio of net result to equity |
| Return on equity 2 | ROEE | Ratio of EBITDA to equity |
Tests of normal distribution
| Test/variable | Doornik-Hansen | Shapiro-Wilk | Lilliefors | Jarque-Bera | ||
|---|---|---|---|---|---|---|
| NPS | 8.87298 | 0.943362 | 0.140474 | 8.38871 | ||
| p | 0.0118374 | 0.00202184 | 0 | 0.0150805 | * | |
| GRS | 1827.37 | 0.333067 | 0.281243 | 10441.5 | ||
| p | 0 | 7.14E–17 | 0 | 0 | ||
| GRE | 241.86 | 0.480801 | 0.317229 | 1578.43 | ||
| p | 3.03E–53 | 6.03E–15 | 0 | 0 | ||
| GRNR | 454.902 | 0.255406 | 0.399927 | 3723.99 | ||
| p | 1.66E–99 | 9.23E–18 | 0 | 0 | ||
| ROA | 43.5001 | 0.855083 | 0.156707 | 62.0592 | ||
| p | 3.58E–10 | 4.17E–07 | 0 | 3.34E–14 | ||
| ROAE | 20.6735 | 0.909117 | 0.105374 | 39.6753 | ||
| p | 3.24E–05 | 4.66E–05 | 0.04 | * | 2.42E–09 | |
| ROS | 1414.12 | 0.327221 | 0.338316 | 3256.38 | ||
| p | 8.46E–308 | 6.08E–17 | 0 | 0.0E+00 | ||
| ROSE | 38.6542 | 0.873817 | 0.157428 | 23.4112 | ||
| p | 4.04E–09 | 1.87E–06 | 0 | 8.25E–06 | ||
| ROE | 56.592 | 0.73652 | 0.14864 | 1470.91 | ||
| p | 5.14E–13 | 2.28E–10 | 0 | 0 | ||
| ROEE | 60.8214 | 0.811631 | 0.21205 | 75.4237 | ||
| p | 6.21E–14 | 1.90E–08 | 0 | 4.19E–17 |
Regression analysis of growth and NPS
| GRE | GRNR | GRS | ||||
|---|---|---|---|---|---|---|
| NPS | Const. | NPS | Const. | NPS | Const. | |
| Coefficient | 0.020407 | -0.64851 | 0.058843 | -3,3264 | 0,003377 | -0,00134 |
| Std. error | 0.015057 | 0.899239 | 0.076608 | 4,57536 | 0,002311 | 0,137994 |
| t-ratio | 1.3553 | -0.7212 | 0.7681 | -0,727 | 1,4618 | -0,0097 |
| p-value | 0.17943 | 0.47307 | 0.44487 | 0,4695 | 0,14804 | 0,99227 |
| Mean dependent variable | 0.461319 | -0.126168 | 0.182342 | |||
| Standard dev. dependent var. | 3.257801 | 16.43895 | 0.500917 | |||
| Sum squared residuals | 776.714 | 20107.61 | 18.29069 | |||
| S.E. of regression | 3.239774 | 16.48407 | 0.497164 | |||
| R2 | 0.024222 | 0.00791 | 0.028065 | |||
| Adjusted R2 | 0.011036 | -0.005497 | 0.01493 | |||
| F(1,74) | 1.836943 | 0.589994 | 2.136756 | |||
| p-value (F) | 0.179432 | 0.444866 | 0.148039 | |||
Mean values of selected variables used in the study (Part I, companies from 1 to 18)
| Company | N | Sales | EBITDA | NR | TA | E | NPS | GRS | GRE | GRNR | ROA | ROAE | ROS | ROSE | ROE | ROEE | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Poczta Polska | 3 | 5486.3 | 170.2 | 0.7 | 4410.3 | 1306 | 43.2 | -0.03 | -0.12 | -1.69 | -0.01 | 0.12 | 0.01 | 0.1 | -0.01 | 0.39 |
| 2 | DHL Express | 3 | 1545.3 | 121.2 | 88.6 | 519.6 | 222 | 64.1 | 0.09 | 0.06 | 0.07 | 0.52 | 0.71 | 0.18 | 0.24 | 1.2 | 1.64 |
| 3 | Raben | 3 | 1469.8 | 115.8 | 76.8 | 754.9 | 252.8 | 67.7 | -0.03 | -0.02 | 0.18 | 0.31 | 0.46 | 0.16 | 0.24 | 0.98 | 1.6 |
| 4 | DPD | 3 | 1073.3 | 153.4 | 79.4 | 1035.7 | 312 | 39.9 | 0.25 | 0.33 | 0.31 | 0.23 | 0.44 | 0.22 | 0.43 | 0.75 | 1.46 |
| 5 | FM | 2 | 880.3 | 54.9 | 24.6 | 350.3 | 106.7 | 58.6 | 0.06 | 0.3 | 0.54 | 0.14 | 0.32 | 0.06 | 0.13 | 0.45 | 1.02 |
| 6 | Jas-Fbg | 1 | 476 | 19.7 | 8.1 | 184.2 | 59 | 52 | 0.04 | -0.05 | 0.03 | 0.05 | 0.11 | 0.02 | 0.05 | 0.14 | 0.34 |
| 7 | DSV | 1 | 437.3 | 11.1 | 6.9 | 131.7 | 39.4 | 64.5 | 0.16 | -0.12 | -0.22 | 0.06 | 0.09 | 0.02 | 0.03 | 0.18 | 0.29 |
| 8 | GLS | 3 | 425.7 | 99.8 | 70.9 | 261.5 | 173.8 | 73.2 | 0.14 | 0.09 | 0.09 | 0.82 | 1.15 | 0.51 | 0.71 | 1.23 | 1.73 |
| 9 | XPO | 2 | 413.4 | 39.4 | 0.8 | 247.8 | 37.7 | 3.6 | -0.02 | -0.13 | -0.23 | 0.01 | 0.32 | 0.01 | 0.19 | -0.03 | 2.05 |
| 10 | Panalpina | 3 | 385.4 | 21.7 | 16.2 | 86.1 | 17.8 | 67.1 | 0.08 | 0.68 | 0.79 | 0.57 | 0.76 | 0.13 | 0.17 | 2.71 | 3.65 |
| 11 | DHL Global Forwarding | 1 | 383.3 | 29.9 | 23.8 | 122.7 | 45.6 | 50 | 0.06 | 0.02 | -0.01 | 0.2 | 0.25 | 0.07 | 0.08 | 0.53 | 0.66 |
| 12 | Link | 3 | 318.9 | 28.3 | 9.4 | 136.1 | 10.3 | 34.9 | 0.23 | 0.22 | 0.46 | 0.21 | 0.62 | 0.09 | 0.27 | 2.64 | 8.18 |
| 13 | Omega Pilzno | 3 | 286.9 | 30.8 | 9.3 | 235.6 | 59.4 | 50.9 | 0.07 | -0.1 | -0.1 | 0.13 | 0.42 | 0.1 | 0.33 | 0.89 | 3.06 |
| 14 | Hellmann | 1 | 282.9 | 2.9 | 1.1 | 76.2 | 21.8 | 85.8 | 0.11 | -0.11 | -0.09 | 0.02 | 0.04 | 0.01 | 0.02 | 0.05 | 0.14 |
| 15 | GEODIS | 3 | 282.5 | 3.1 | 1.6 | 75.4 | 2.3 | 81.1 | 0.2 | 0.52 | -0.08 | 0.07 | 0.13 | 0.02 | 0.04 | 2.44 | 5.61 |
| 16 | DHLSupplychain | 3 | 239.6 | 9.7 | 4.3 | 94.7 | -22.7 | 28.2 | 0.24 | 0.35 | -0.42 | 0.14 | 0.31 | 0.06 | 0.13 | -0.62 | -1.36 |
| 17 | Arvato | 3 | 229.8 | 10.9 | 0.8 | 197.1 | 18.2 | 61.1 | 0.3 | 1.38 | -2.63 | 0.01 | 0.16 | -0.01 | 0.14 | 0.05 | 1.73 |
| 18 | C.Hartwig | 1 | 214.7 | 5.2 | 3.1 | 65 | 4.3 | 74.5 | -0.04 | -1.59 | -1.21 | 0.05 | 0.08 | 0.02 | 0.03 | 0.71 | 1.2 |
Mean values of selected variables used in a study (Part II, companies from 19 to 34)
| Company | N | Sales | EBITDA | NR | TA | E | NPS | GRS | GRE | GRNR | ROA | ROAE | ROS | ROSE | ROE | ROEE | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 19 | Spedimex | 3 | 166.2 | 3.1 | 0.3 | 49.3 | 10.4 | 37.1 | 0.04 | 0.11 | 1.04 | 0.02 | 0.19 | 0.01 | 0.06 | 0.08 | 0.89 |
| 20 | Maszoński | 3 | 162.6 | 27.7 | 23.5 | 149.1 | 34.8 | 95.9 | 1.56 | 6.39 | 32.71 | 0.48 | 0.57 | 0.46 | 0.54 | 2.03 | 2.4 |
| 21 | Delta Trans | 1 | 153.7 | 15.1 | 4.1 | 79.3 | 36.2 | 59.1 | 0.01 | -0.03 | 0.27 | 0.06 | 0.2 | 0.03 | 0.1 | 0.12 | 0.42 |
| 22 | Damco | 1 | 138.7 | 4.1 | 2.9 | 63.8 | 32 | 15 | 0.03 | -3.48 | -3 | 0.05 | 0.07 | 0.03 | 0.03 | 0.09 | 0.13 |
| 23 | Farmada | 2 | 125.6 | 18 | 13.4 | 32 | 21.6 | 67.6 | 0.14 | 1 | 0.94 | 0.84 | 1.13 | 0.22 | 0.29 | 1.25 | 1.68 |
| 24 | Fiege | 1 | 119.1 | 17.9 | 8.3 | 85 | 29.6 | 50 | 0.01 | 0.18 | 0.06 | 0.1 | 0.22 | 0.07 | 0.16 | 0.28 | 0.61 |
| 25 | Diera | 3 | 117.9 | 2.5 | 2 | 30.5 | 8 | 72.8 | 0.04 | 2.08 | -33.79 | 0.19 | 0.24 | 0.05 | 0.07 | 0.52 | 0.68 |
| 26 | ID Logistics | 3 | 111.8 | 2.6 | -1.3 | 36.8 | -3.5 | 46.7 | -0.02 | -5.06 | -0.78 | -0.12 | 0.2 | -0.04 | 0.08 | -2.08 | 6.95 |
| 27 | Uni-Logistics | 1 | 102.4 | 3 | 1.7 | 22.3 | 4.5 | 50 | 0.22 | 0.54 | 0.57 | 0.08 | 0.14 | 0.02 | 0.03 | 0.37 | 0.67 |
| 28 | Seifert | 2 | 89.6 | 2.6 | 2 | 22.1 | 4.8 | 26.9 | 0.19 | 0.29 | 0.21 | 0.18 | 0.24 | 0.05 | 0.06 | 0.83 | 1.1 |
| 29 | IFB | 3 | 55 | 2.6 | 2 | 13 | 3.7 | 66.1 | 0.19 | 0.26 | 0.25 | 0.47 | 0.59 | 0.11 | 0.14 | 1.85 | 2.37 |
| 30 | PartnersPol | 1 | 54.2 | 1.4 | 0.8 | 15.7 | 7.7 | 47.3 | 0.02 | 8.45 | -3.28 | 0.05 | 0.09 | 0.02 | 0.03 | 0.1 | 0.19 |
| 31 | Allport | 3 | 53.8 | 3.1 | 2.6 | 14.3 | 7.8 | 61.6 | 0.12 | 0.12 | 0.22 | 0.57 | 0.67 | 0.15 | 0.17 | 1.07 | 1.26 |
| 32 | DSV | 3 | 51.8 | 2.3 | 0.3 | 27.8 | 8.1 | 22.4 | 0.47 | 0.32 | -0.52 | 0.02 | 0.23 | 0.01 | 0.13 | -0.04 | 0.83 |
| 33 | Marathon | 2 | 48.8 | 11.8 | 5.4 | 45 | 13.2 | 51.7 | 0.16 | 0.57 | 2.09 | 0.23 | 0.54 | 0.22 | 0.48 | 0.79 | 1.84 |
| 34 | VGL | 2 | 6.6 | 0.7 | 8.2 | 15.5 | 13.2 | 64 | 0.32 | 2.25 | 0.96 | 1.06 | 0.1 | 2.52 | 0.22 | 1.25 | 0.11 |
| 76 | 564.2 | 36.7 | 17.5 | 350.7 | 104.5 | 54.4 | 0.19 | 0.47 | -0.13 | 7.65 | 11.74 | 5.46 | 5.75 | 22.71 | 55.34 |
Descriptive statistics of selected variables in the period between 2014 and 2016
| Variables | Mean | SD | Median | Min | Max | Skewness | Kurtosis |
|---|---|---|---|---|---|---|---|
| NPS | 54.3855 | 24.8462 | 58.3000 | –20.0000 | 100.000 | –0.7746 | 0.4991 |
| GRS | 0.1823 | 0.5009 | 0.0943 | –0.1098 | 4.246 | 7.1909 | 55.5921 |
| GRE | 0.4613 | 3.2578 | 0.1508 | –16.0941 | 19.4218 | 1.1577 | 22.2057 |
| GRNR | –0.1262 | 16.4389 | 0.0364 | –101.858 | 98.4515 | –0.2878 | 34.2880 |
| ROA | 0.1006 | 0.1215 | 0.0621 | –0.0973 | 0.5335 | 1.6242 | 3.0076 |
| ROAE | 0.1544 | 0.1158 | 0.1369 | –0.0413 | 0.5673 | 1.3022 | 2.3971 |
| ROS | 0.07173 | 0.2024 | 0.0263 | –0.0260 | 1.3573 | 5.4915 | 30.1281 |
| ROSE | 0.0756 | 0.0632 | 0.0598 | –0.0109 | 0.2591 | 1.2583 | 1.0294 |
| ROE | 0.2987 | 0.5099 | 0.3232 | –2.9689 | 1.4221 | –3.2564 | 20.5446 |
| ROEE | 0.7281 | 0.8062 | 0.5496 | –0.6704 | 3.4954 | 1.7762 | 3.3465 |