A SSCCE for an issue with elm-lang/html. You can paste it to http://elm-lang.org/try.

SSCCE.elm

import Html exposing (..)
import Html.Attributes exposing (..)
import Json.Encode


valueAttributes =
    [ value ""
    , property "value" (Json.Encode.string "")
    , attribute "value" ""
    ]


selectOptions =
    List.map
        (\x -> option [ value <| toString <| fst x ] [ text <| snd x ])
        [ ( 1, "Foo" ), ( 2, "Bar" ), ( 3, "Baz" ) ]


requiredSelect valueAttribute =
    select
        [ required True ]
    <|
        (option [ valueAttribute ] [ text "Please choose an option" ])
            :: selectOptions


main =
    Html.form []
        [ div [] <| List.map requiredSelect valueAttributes
        , button [ type' "submit" ] [ text "Submit" ]
        ]