At long last the 2016 presidential nomination contests have finally started with the conclusion of the first contest, and we now have the first solid glimpse at voter participation.

The Iowa Republican caucus blasted through its 2012 record of 121,354, but Democrats could not keep pace with 2008, when 236,000 Iowans participated in the Democratic caucus. Iowa's turnout rate was therefore down slightly from the 16.1% in the 2008 election, the last election when both parties last held competitive contests.

What Iowa Means for the Remaining Presidential Nomination Contests

It may be tempting to directly overlay Iowa's turnout onto the 2008 turnout to project overall turnout in the coming presidential nomination contests. In 2008, a total of 61.4 million people were reported to have participated in a caucus or primary, or 29% of those eligible to vote. (This was less than half of the 131.3 million or 62% that voted in the Nov. election.) If the Iowa participation remained at similar levels, we might expect 28% of those eligible will vote, or about 65 million people.

This approach is flawed in ways that expose deficiencies in the timing of presidential nomination contests.

The most obvious issue is candidate competition, which is related to contest timing. Dark horse candidates race alongside frontrunners in the earliest contests hoping to earn a surprising showing which will catapult them to their party's nomination. The belief is grounded in the folklore of Jimmy Carter's surprising victory in the 1976 Iowa caucus.

The horserace analogy is particularly apt, because once the candidates clear the initial poles, the front running candidates separate themselves from the pack and it becomes increasingly clear to the voters and campaigns which candidates have a realistic chance of winning the nomination. When this happens, voter participation usually begins to fade.

The dynamic between competition and timing is exemplified by the early primary contests. In 2008, 54% of eligible New Hampshire voters participated in their primary, a turnout rate higher than three states in their November election. Oregon was the next highest state with a primary turnout rate of 43%. Even Iowa's caucus - a low turnout event due to voters' significant time commitment to participate - had a turnout of 16%, which was rivaled turnout rates in Louisiana's and New York's primaries, both below 20%.

An important takeaway from New Hampshire's past experience is that primary voter turnout will likely be high, about 50% of those eligible, and polls' likely voter models should have looser likely voter screens.

But after we get past the first two nomination contests, turnout will likely decline. How much will depend on how far candidates remain competitive into the nomination calendar.

In 2008, an extended battle between Clinton and Obama, which kept turnout above a quarter of those eligible in most states, averaging about 30%, until the end.

Without extended competition, interest in the presidential nomination fades quickly. In 2012, without a serious Democratic nomination contest and with the Republican nomination wrapped up, turnout in four of the five April 24 primaries evaporated to the low single digits.

No one knows how long the Democratic and Republican contests will remain competitive, so we cannot reliably forecast overall participation. However, looking forward to New Hampshire, if 2012 is a guide the first primary should have a turnout rate of around fifty percent. After that, turnout will remain somewhere in the thirty to forty percent range and diminish as competition fades.

An important caveat hidden in the preceding discussion is that while competition in the presidential nomination contest may eventually wane, in only some states is the presidential contest the only race on the ballot. Competition in state races on the ballot can supplement and supplant presidential competition, drawing in voters who wish to participate in their selection of state candidates. Pennsylvania was the only state to have a concurrent presidential and state primaries on April 24, 2012, which explains why turnout was substantially higher than the four other states that held only presidential contests on that date.

My Proposed Reform: Move the Presidential Calendar Later

A simple way to increase participation in primaries is therefore to hold only one primary where both presidential delegates and state offices are chosen. Another substantial benefit is that statewide elections are expensive to run. Holding one less primary election would reduce election costs by the tens of millions for the two-thirds of states that decoupled their presidential and state primaries in 2016.

If higher turnout and lower costs were not enough benefits, state politicians generally like to hold their primaries later in the election year so there is not an extended dead period between the primary and general election. When Illinois moved its primary to February's Super Tuesday in 2008, they kept their state offices on the ballot. Unhappy with the experience, they moved their primary later to March in 2012. Holding more concurrent primaries would compress the presidential election calendar as states opted to hold later primaries.

Higher participation, lower costs, and a shorter presidential campaign? What is not to like about this simple reform? Well, states want a say in who will be president, and want to hold their nomination contests before a winner is chosen. The siren call of front-loading is so strong that it nearly caused the 2012 election to start in 2011 as states stumbled over each other as they elbowed their way to the front. The parties instituted stronger sanctions for parties that go before March 1, 2016 with exemptions granted to Iowa, New Hampshire, South Carolina, and Nevada. No state dared cross the line in 2016. Since the party sanctions appear so powerful, at least for the moment, the parties could push the starting line back even further, to April or even May.

What Iowa Means for November

There is a long way to go until the general election. Iowa provides the first early indicator of the electorate's interest, and it appears healthy, on par with 2008. It may be tempting to infer from higher turnout in the 2008 Democratic Iowa caucus, compared to the Republican caucus, that higher Republican engagement in 2016 will carry forward to November. However, a number of studies find that comparatively older people, and consequently and more Republicans, participate in recent lower turnout elections. This is part of the reason why Republicans did well in the past two midterm elections, and why all things equal, we should expect more Republicans to participate in caucuses held in a battleground state. Further consider that Republican turnout was 40% greater than Democrats in 2000, and the general election went into overtime. Much will pass before November, but the tea leaf to read here is that without knowing who the nominees will be, November promises to be a highly competitive election.