Unhappy that Mayor Mike McGinn–citing shortfalls in the city budget–pushed the pause button on a plan to hire 21 new patrol officers by year’s end, the Downtown Seattle Association has released a report indicating that Seattle has less officers per capita than it did a decade ago. But exactly how many police officers does a city of 600,000 people need?In a Seattle Times

editorial, the DSA writes that back in 2000 Seattle was a city of 563,373. At the time, SPD employed 1,264 officers. That’s 2.24 officers per every 1000 Seattleites. Ten years later, Seattle has 617,334 residents with 1,338 officers, or 2.16 officers per thousand residents. “We can’t sustain safe and vibrant neighborhoods with a shrinking police force relative to the overall size of the city.” It’s an intuitive argument–as a population increases, so should the number of sworn officers policing it. But balancing a budget is hard. And even in the most flush of times, determining the number of sworn officers it takes to ensure public safety is far from an exact science. That goes double in a city like Seattle where the crime stats tend to confuse the debate.As Mayor McGinn points out, the number of major crimes committed in Seattle has tumbled in recent years. But SPD’s latest stats indicate that in downtown Seattle, property crime is up. So, if you’re one of the DSA’s patrons, you’re more than likely in the pro-police-force-expansion camp. UCLA Professor of Public Policy Mark Kleiman, who last month spoke at a city-council sponsored town hall on public safety says there’s no generally accepted benchmark for appropriate police staffing levels. A decent police to population ratio is one and a half to two officers per 1,000 residents, he adds.That puts Seattle in range at least. With the weather warming up, however, downtown’s ever-fluctuating population of commuters, tourists and boozers is only going to increase. And if the crime trends hold, the DSA is only have more grist for their argument.