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dissertation in pdf-format - Aalto-yliopisto

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Characteristics of successful gazelles 31<br />

HS are each allocated a value 1, whilst 0 denotes the absence of HG, high success<br />

or both.<br />

where<br />

y i = + (X) + , (5)<br />

y 0 for low growth or success<br />

1, for HG and high success<br />

X matrix of the predictor variables.<br />

The probability that yi = 1 will be<br />

i i i i<br />

<br />

P y =1 x = exp x <br />

1 + x <br />

(6)<br />

The list of predictor variables is presented <strong>in</strong> Appendix 3. In the logistic regression the<br />

impact of changes to the coefficients on the probability of an event occurr<strong>in</strong>g depends on<br />

the <strong>in</strong>itial probability of the event.<br />

In Table 4, LRA is presented first without tak<strong>in</strong>g <strong>in</strong>to account a priori probabilities<br />

(Model 1) and thereafter with matched selection of NHS and NHG bus<strong>in</strong>esses<br />

(Table 4, Model 2). In addition to the number of auxiliary bus<strong>in</strong>ess names, age, bus<strong>in</strong>ess<br />

volume factor and services as a branch of <strong>in</strong>dustry, which were found to be significant <strong>in</strong><br />

the DA, trade and manufactur<strong>in</strong>g as well as the liquidity factor were also found to be<br />

statistically significant <strong>in</strong> the LRA. In model 2, which <strong>in</strong>cluded a matched pair<br />

comparison and cross validation, age and services as a branch of <strong>in</strong>dustry were no longer<br />

statistically significant. The number of auxiliary bus<strong>in</strong>ess names was the only variable<br />

that decreased the odds ratio with respect to classification as a HG and HS firm.<br />

These results are partly <strong>in</strong> the l<strong>in</strong>e with the conclusion of Ettl<strong>in</strong>ger and Tufford (1996)<br />

that high perform<strong>in</strong>g firms seem to <strong>in</strong>vest <strong>in</strong> labour; however, <strong>in</strong> the current study it is<br />

not possible to tell whether labour <strong>in</strong>vestments exceeded capital <strong>in</strong>vestments made by<br />

the firms.<br />

In Model 1 the overall classification rate of the model was almost 80%, but this was<br />

due to the correct classification of NHS and NHG firms; <strong>in</strong> contrast, the correct<br />

classification of HS and HG firms was very poor (26.7%). It should be noted that <strong>in</strong> the<br />

logistic regression model it is always possible to achieve at least 50% accuracy by simply<br />

sett<strong>in</strong>g the prediction for each observation to correspond to the most frequent outcome<br />

(Hoetker 2007). Thus the model is not appropriate s<strong>in</strong>ce it does not reach the level of a<br />

priori probability (0.5) for the HS and HG group.<br />

When a priori probabilities are taken <strong>in</strong>to account and similar numbers of cases are<br />

selected for the analysis, the results change so that age is no longer a statistically<br />

significant variable (Table 3, Model 2). Moreover different dummies for branch of<br />

<strong>in</strong>dustry are statistically significant <strong>in</strong> the forced model. The overall classification rate of<br />

the model was 63.8%. The correct classification rate of selected cases was 62.3% for<br />

NHG and NHS firms and 65.3% for HG and HS firms. Unselected cases all belonged to<br />

NHS and NHG and their classification rate was 66.3%.

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