What else would you want on a typical pivot table...say for posts and tags.

migration.php

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;

class PivotPostTagTable extends Migration {

    /**
	 * Run the migrations.
	 *
	 * @return void
	 */
	public function up()
	{
		Schema::create('post_tag', function(Blueprint $table) {
			$table->integer('post_id')->unsigned()->index();
			$table->integer('tag_id')->unsigned()->index();
			$table->foreign('post_id')->references('id')->on('post')->onDelete('cascade');
			$table->foreign('tag_id')->references('id')->on('tag')->onDelete('cascade');
		});
	}



	/**
	 * Reverse the migrations.
	 *
	 * @return void
	 */
	public function down()
	{
		Schema::drop('post_tag');
	}

}

I know you said you were going to leave it off, but just for reference, I +1 the addition of timestamps

Could you make the foreign key constraints optional (default on is fine).