JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://cloud.github.com/downloads/SteveSanderson/knockout/knockout-2.1.0.js"></script>
<select id="testSelect" data-bind="value: stateString">
    <option value="true">true</option>
    <option value="false">false</option>
</select>

JavaScript

var model = {
    state: ko.observable(false)
};

model.stateString = ko.computed({
    read: function() { return (this.state() ? "true" : "false"); },
    write: function(value) { this.state(value == "true" ? true : false); }
}, model);

ko.applyBindings(model);


setTimeout(function() {
    model.state(true);    
}, 1500);

setTimeout(function() {
    $("#testSelect").val("false");
}, 3000);