It's about as rare for an American woman to have an abortion today as it was before the Supreme Court's decision in Roe v. Wade 41 years ago. As David Frum notes in a commentary at The Atlantic, that's apparently because unmarried women are no longer afraid of bearing children out of wedlock.

Having a baby as a single woman used to be socially unacceptable, but it's become a fact of American life. About 41 percent of children born in the United States in 2012 were born to unmarried mothers, according to the Centers for Disease Control and Prevention, a tenfold increase from 4 percent in 1940. It seems unwed women would now rather carry pregnancies to term than seek abortions.

Frum ascribes this change to conservative political strategy on abortion. He argues that pro-life activists have made their case convincingly without also making a case for marriage, with the result that women are choosing to have children but not to marry. That might be giving the conservative movement too much credit. Public attitudes about abortion have held steady in recent years, even as the rate of births to unmarried mothers has continued its steep climb. It looks as though unmarried women are making decisions about pregnancies more or less on their own.

Whatever the explanation, Frum's conclusion seems sensible: the best way to get people to create and stay in families is with policies that make raising a family genuinely easier. Here are a few ideas:

-- Frum suggests wage subsidies, which would make parents more attractive to employers.

-- Expanding the child tax credit would help families financially. Another approach would simply be to send mothers a monthly check.

--  Offering universal pre-kindergarten would also ease the cost of child care for young families.

--  Guaranteeing paid leave for new parents couldn't hurt.

--  Finally, Obama's executive action on immigration will keep many immigrant families together.

Frum opposed that last one on the principle of the separation of powers, while the others would be costly to implement. In all, these aren't the kind of policies that conservative lawmakers would usually consider, but they might have to give these ideas some thought anyway if they're serious about promoting family values.

Correction: An earlier version of this newsletter misstated the number of years that have elapsed since Roe v. Wade. The decision was 41, not 31, years ago. This version has been corrected.

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What's in Wonkbook: 1) Obama's new policies for police 2) Opinions: Obesity, the economy, Detroit 3) Oil goes for a ride 4) Rape at U.Va. 5) Eminem's lyrics are read from the Supreme Court's bench, and more

Number of the day: $46 billion. That's how much the Pentagon spent developing new weapons that were terminated before they ever became operational. Even costlier pie-in-the-sky prototypes are still being worked on, though it's hard to say how many of them will actually be deployed. Christian Davenport in The Washington Post.

Chart of the day:

Whites have become far less racist over the past four decades, as Chris Rock rightly notes in an interview. Still, more than a quarter of whites think homeowners should be allowed not to sell their property to blacks because of their race. Christopher Ingraham in The Washington Post.

1. Top story: Obama changes how police handle heavy weapons

The president announces a few small checks on police militarization. The administration is setting new requirements for transparency and training from police departments seeking money or heavy equipment from the federal government to be sure the police are putting military-grade weapons to good use. The additional paperwork won't do much to reduce the volume of transfers, though. "The limited nature of the White House response also reflects the reality that transferring military-style surplus gear to police departments remains politically popular in Congress and in the municipalities." Mark Landler in The New York Times.

BADGER: The new requirements leave unanswered the most important question. It's fine to say you're going to train police officers to use military-style equipment properly, but what exactly is the right way for a cop to use a mine-resistant, ambush-protected vehicle? In other words, why do police need this gear at all? The Washington Post.

Obama is also asking Congress for $75 million for body cameras for police. The president wants to help police departments pay for cameras for their officers. Had Officer Darren Wilson been wearing one when he shot and killed Michael Brown, it would have recorded their entire interaction. Andrea Peterson in The Washington Post.

Peaceful protests continued nationwide on Monday. Demonstrators blocked roads, and students didn't attend high school and university classes. Monica Davey, John Eligon and Jess Bidgood in The New York Times.

Rioters explain why they turned to destruction.  "I want to do what they did to me. I want to physically fight the police for all the stuff they have done to me," one man says. Yamiche Alcindor in USA Today.

KLEIN: Bias in policing is complicated, but no less real. There are all kinds of factors that determine how likely police are to stop someone. None of them really explain why cops are so much more likely to stop blacks. Vox.

BROOKS: Ferguson shows the need to talk about class as much as race. As important as the prejudice of whites toward blacks is the bias of well-off people toward those living, like Brown, on the margins of the economy. Creating a more socially mobile country, with real opportunities for everyone, would go a long way toward bringing the country together and reducing that class prejudice. The New York Times.

The president also said nothing about gathering data on the use of deadly force.  "To this day, no annual report provides authoritative data on killings by police and the circumstances in which they occur. That’s the kind of truth that the federal government is uniquely equipped to seek, and to tell." The Washington Post.

2. Top opinions: Obesity, the economy, Detroit

NOAH SMITH: As a country, "we are drowning in fat." Obesity isn't often talked about as one of the most serious crises that policymakers need to deal with right away, but it is. Obesity damages not just Americans' health but also the national economy and military preparedness. Bloomberg.

RAMPELL: The United States beat the financial crisis. Serious mistakes were made, to be sure, and many people are still looking for work. Yet Obama's fiscal stimulus, along with easy monetary policy, has put this country in a much better position than just about any other. The Washington Post.

RITHOLTZ: Disappointing Black Friday sales are meaningless. The trade organization that releases the surveys doesn't have the data to come to any firm conclusions. Retail sales overall have been strong this year and will likely remain so through the holidays. Bloomberg.

AVENT: It's too early to declare victory. Interest rates will have to remain at zero for some time, and any negative shock to the economy would cause a recession. The Economist.

Detroit gets a second chance. Now is the moment for the city to pursue aggressive reforms: encouraging residents to move into the city's center, expanding mass transit and eliminating inefficiency in the municipal bureaucracy. If Detroit can't attract new businesses, the same problems it's always had will eventually force it back into bankruptcy. Bloomberg.

Hip-hop interlude: Wu-Tang's new album, "A Better Tomorrow," drops Tuesday. Sasha Frere-Jones in The New Yorker.  Listen here.

3. Oil prices reach five-year low

The price for Brent crude had recovered by Tuesday. Prices have fallen more than a quarter this year, and they reached their lowest level since October 2009 on Monday before recovering to near $73 a barrel. Reuters.

Lower oil prices change everything. Forecasts for cheap oil next year are already having profound effects:

-- Stock prices for major oil producers have also fallen.

-- The slide in prices weakens Russia and Iran, exacerbating the effects of Western sanctions.

-- Fracking will continue in the United States, but at a slower pace.

-- Federal Reserve officials say the slide in oil prices will help U.S. consumers, who are saving $630 million a day on gasoline in total.

Steve Mufson in The Washington Post.

What's driving the decline in prices? There are a few reasons.

-- First, OPEC is now deeply divided over how much oil to produce. The member states voted Thursday not to stabilize prices by cutting production.

-- And production in the United States is booming.

-- Internationally, a weak global economy is burning less fuel.

Chris Mooney in The Washington Post.

EL-ERIAN: The decline in prices will help the poor and working class, but carries risks. For one, investment in new, clean technologies will be hampered by low energy prices. Bloomberg.

4. State lawmakers respond to U.Va. story

Virginia legislators want sexual assaults reported to the police. New bills announced Monday would require college administrators to notify law enforcement of any complaints about sexual violence. Similar bills failed in 2011. Karin Kapsidelis in the Richmond Times-Dispatch.

People are questioning the Rolling Stone story that started the controversy. The reporter did not name any of the people involved and didn't talk to the alleged rapists, but an editor for the magazine says he is confident that the story is real and that he knows the identities of the subjects. Paul Farhi in The Washington Post.

5. In case you missed it

John Roberts quotes Eminem. The Supreme Court heard a case on Monday about whether the freedom of speech extends to threats made online. The chief justice wondered whether, if violent language about a specific person published online constituted a threat, Eminem's disturbing songs about his wife would have been criminal. Dustin Volz in National Journal.

A milestone is reached in stopping AIDS. For the first time, more people are beginning to receive treatment than are being infected, which means that patients and doctors are controlling the virus. Still, there's work to be done, and the people who have the virus now are more likely to be members of groups that are harder for health workers to help. Jason Millman in The Washington Post.

Patent lawsuits are on the decline, for the first time in years. The Supreme Court's recent decisions have made it easier for defendants to recover costs in frivolous lawsuits and to challenge overly broad patents. The result is that real entrepreneurs are more free to pursue their ideas without worrying about whether they're infringing on some troll's bogus patent. James Bessen in The Atlantic.