All you have to do is pull up your guild tab and hover your mouse over the shield graphic in the guild screen to see this is true.
◦Note: Inactive accounts do not hurt your guild renown production or decay. However recent departures do. Thus booting inactive accounts actually hurts your guilds overall renown production. As your modified account size will go up by one for 2 weeks after the last character from that account is removed from the guild. You'll also lose 25% of the renown that character gained while a member of the guild.