TY - JOUR
T1 - Marginal Effects in Interaction Models
T2 - Determining and Controlling the False Positive Rate
AU - Esarey, Justin
AU - Sumner, Jane Lawrence
PY - 2018/8/1
Y1 - 2018/8/1
N2 - When a researcher suspects that the marginal effect of (Formula presented.) on (Formula presented.) varies with (Formula presented.), a common approach is to plot (Formula presented.) at different values of (Formula presented.) along with a pointwise confidence interval generated using the procedure described in Brambor, Clark, and Golder to assess the magnitude and statistical significance of the relationship. Our article makes three contributions. First, we demonstrate that the Brambor, Clark, and Golder approach produces statistically significant findings when (Formula presented.) at a rate that can be many times larger or smaller than the nominal false positive rate of the test. Second, we introduce the interactionTest software package for R to implement procedures that allow easy control of the false positive rate. Finally, we illustrate our findings by replicating an empirical analysis of the relationship between ethnic heterogeneity and the number of political parties from Comparative Political Studies.
AB - When a researcher suspects that the marginal effect of (Formula presented.) on (Formula presented.) varies with (Formula presented.), a common approach is to plot (Formula presented.) at different values of (Formula presented.) along with a pointwise confidence interval generated using the procedure described in Brambor, Clark, and Golder to assess the magnitude and statistical significance of the relationship. Our article makes three contributions. First, we demonstrate that the Brambor, Clark, and Golder approach produces statistically significant findings when (Formula presented.) at a rate that can be many times larger or smaller than the nominal false positive rate of the test. Second, we introduce the interactionTest software package for R to implement procedures that allow easy control of the false positive rate. Finally, we illustrate our findings by replicating an empirical analysis of the relationship between ethnic heterogeneity and the number of political parties from Comparative Political Studies.
KW - interaction
KW - political parties
KW - quantitative methods
UR - http://www.scopus.com/inward/record.url?scp=85042126558&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85042126558&partnerID=8YFLogxK
U2 - 10.1177/0010414017730080
DO - 10.1177/0010414017730080
M3 - Article
AN - SCOPUS:85042126558
VL - 51
SP - 1144
EP - 1176
JO - Comparative Political Studies
JF - Comparative Political Studies
SN - 0010-4140
IS - 9
ER -