The results of random-effect model
(pD=20.9 and DIC=23.3) were similar to the fixed-effect model (pD=15.9 and DIC=67.7).
If significant heterogeneity was present (P < 0.1, [I.sup.2] > 50%), a random-effect model
Next, Columns (7) through (9) report results from the application of fixed-effect model, Columns (10) through (12) provides a similar report from the estimation of a random-effect model
, and, finally, the last three columns do the same job for a random-coefficient model, where coefficient randomness is assumed to apply only to the coefficient of our concern, the level of corruption (cp i).
A random-effect model
was used to summarise the results when the heterogeneity was high or medial, otherwise a fixed-effect model was used.
Heterogeneity was measured using [I.sup.2].18 When [I.sup.2] is less than 50% and p>0.10, the results were considered homogeneous and the fixed-effect model was used; when [I.sup.2] is greater than 50% but less than 75%, results were considered heterogeneous and the random-effect model
A fixed-effect model (Mantel-Haenszel) was applied in case of absence of heterogeneity between studies and otherwise a random-effect model
Homogenous data was calculated using the fixed-effect model, and random-effect model
was employed when there was statistically significant heterogeneity.
Two approaches are developed to capture the unobserved heterogeneity: fixed-effect model and random-effect model
. The fixed-effect model examines cross-sectional and/or time-serial difference in the intercept term.
Lagrangian multiplier test statistic of 21.78 and p-value = 0 supports the preference for the random-effect model
rather than for the pooled model.
In a random-effect model
, there is an extra factor added in the equation to control the country-specific random element.
According to the random-effect model
, each respondent bases both the initial and the follow-up questions on a WTP amount that has mean value equal to the respondent's true WTP; but the actual WTP amount used when responding to a particular payment question is subject to random error.