html output.html

<p>
    <select name="Associations[0].SomeId">
      <option value="">Select...</option>
      <option value="7">AAA</option>  <!-- why isn't a value in the dropdown selected? -->
      <option value="8">BBB</option>
      <option value="9">CCC</option>
    </select>
    <!-- but yet, the value here is populated -->
    <input name="Associations[0].Foo" type="text" value="whatever">
</p>
<p>
    <select name="Associations[1].SomeId">
      <option value="">Select...</option>
      <option value="7">AAA</option>   <!-- why isn't a value in the dropdown selected? -->
      <option value="8">BBB</option>
      <option value="9">CCC</option>
    </select>
    <!-- but yet, the value here is populated -->
    <input name="Associations[1].Foo" type="text" value="something else">
</p>

razor view.cshtml

@model MyNamespace.SomeViewModel

@for (int i = 0; i < Model.Associations.Count; i++)
{
    <p>
        @* SomeId property has an interger value, like 7 *@
        @Html.DropDownListFor(a => a.Associations[i].SomeId, Model.SomeList, "Select...")

        @* Foo property has a string value, like "whatever" *@
        @Html.TextBoxFor(a => a.Associations[i].Foo)
    </p>
}