You have to set the value and text of select html control. The sintaxe is:

<option value='your value'>text</option>

Try something like this:

<select>
    @foreach (var item in Model)
    {
        <option value='@item.ResponseIdentifier'>@item.ResponseIdentifier</option>
    }
</select>

Or, in my opinion it is better. Your action on the controller, you could define a key on the ViewBag to fil lthe dropdownList, for sample:

ViewBag.Cities = new SelectList(new[]
{
    new { Id = "1", Name = "New York" },
    new { Id = "2", Name = "São Paulo" },
    new { Id = "3", Name = "London" },
}, "Id", "Name");

To fill this ViewBag, it could come from a database or xml file, anywhere. In your View, your could use this item on ViewBag to fill a DropDownList using the Html helpers, for sample:

@Html.DropDownList("City", (IEnumerable<SelectListItem>)ViewBag.Cities, new { style = "max-width: 600px;" })