use Devel::Peek qw( Dump );

my $s1 = "Ein Ökonomisches Modell";
my $s2 = "Ein \326konomisches Modell";

Dump($s1);
Dump($s2);

utf8::upgrade( $s1 );
utf8::upgrade( $s2 );

Dump($s1);
Dump($s2);