First, our dependent variable is the change in the quality of institutions between 1990 and 2000 while the explanatory emigration rate pertains to 1990.
We included unemployment, income, and robbery rates as explanatory variables because STD rates also have been linked to social determinants of health (14, 15 ).
The coalescence model, and its extension to evolution between populations, requires a single explanatory parameter, the rate of gene acquisition ω.
To obtain as many percentile groups as possible to visualise threshold effects, while avoiding unstable results due to small numbers in each group, we classified our main explanatory variable, GP rate into quintiles.
For all four groups we conducted regression analysis based on 880 out of 1,038 non-overlapping windows of size 1 Mb, where data on the six possible explanatory variables recombination rate, divergence, gene density, GC content, dS and dN were available.
The relationship between the main explanatory variable (LTC-rate) and outcome variable (HD-rate), weighted by population size in each unit of analysis, was examined in a crude model, a model adjusted for age, a model adjusted for age and each of the variables in Table 1, and finally in a full model where all interacting and confounding variables were included.
Among the explanatory variables for rates of volume loss, Aβ1 42 and ApoE were the only ones that had a significant interrelationship (r = −0.58) with Aβ1 42 contributing 1.5 times as much to the variability of hippocampus atrophy rates than ApoE.
Our main explanatory variable, LTC-rate, was a composite variable consisting of number of recipients of municipal LTC (both at home and in institution) per 1000 inhabitants in each unit of analysis.
In columns (1) and (3) the instrumented explanatory variable is enrollment rate; in columns (2) and (4) the instrumented explanatory variable is female enrollment rate.
When investigating how indels relate to the log-transformed recombination rate, all explanatory variables used in the prediction of the indel counts described above were used except for the recombination rate, variables related to fixed human variation and chimp variation.
