The Hours and Academic Achievement
时间分配与学业成就
Adults love controlling the way kids spend the hours of the day. What’s the payoff for all their meddling? Hofferth and Sandberg’s “How American Children Spend Their Time” (Journal of Marriage and the Family) provides some fascinating answers for kids ages 0-12.
成年人总喜欢控制孩子们每天支配时间的方式。然而这样多管闲事的结果是什么呢？Hofferth和Sandberg在“美国儿童如何支配时间”（刊于《婚姻与家庭杂志》）一文中针对12岁以下儿童给出了一些让人着迷的答案。
After compiling the basic facts about kids’ time use from the 1997 Child Development Supplement to the PSID, H&S regress measures of academic achievement on time use, controlling for child’s age, gender, race, ethnicity, head of household’s education and age, plus family structure, family employment, family income, and family size. All test scores have a mean of 100 and a standard deviation of 15, and all time use is expressed in hours per week.
在将1997年《儿童发展附录》中有关儿童时间使用的基本事实编入PSID之后，Hofferth和Sandberg对学业成就和时间利用进行了分组回归，分别控制了儿童年龄、性别、种族、民族、家长教育程度与年龄，以及家庭结构、家庭就业状况、家庭收入和家庭规模等变量。所有测试结果都以100为均值且以15为标准差，所有的时间利用都以每周的小时数表示。
结果：
The big result is the lack of results. Controlling for family and child background, time in school and studying barely help – and television viewing barely hurts. Contrary to wishful assertions that exercising the body improves the mind, sports don’t matter either. Out of nineteen activities, only two predict greater academic success across the board: reading and visiting.
最大的结果就是没有结果。控制家庭和儿童的背景因素之后，在学校和学习中花费的时间鲜有助益，而看电视也看不出什么坏处。运动和锻炼身体有益心智这样的断言，也被证明是一厢情愿的。在19种活动之中，只有两项活动预示着学业成功：阅读和游历。
The estimated effect of visiting is modest. Reading, however, is a huge deal. Ceteris paribus, 10 extra hours of reading per week raise letter-word comprehension by .5 SDs, and passage comprehension, applied problems, and calculations scores by .4 SDs.
评估中参观的影响适中，而阅读则关系显著。其他条件相同时，每周10小时的额外阅读，会将字词理解能力提高0.5个标准差，段落理解能力、应用问题能力和计算能力也会提高0.4个标准差。
Despite obvious worries about reverse causation – smart kids enjoy books more – much of this is plausibly causal. After all, many smart kids don’t read much, and H&S include a lot of solid control variables. And you really can learn a lot from books.
尽管相反的因果关系显然也值得考虑——聪明的孩子更热衷读书——但上面提及的因果关系貌似更可信。毕竟，很多聪明孩子不怎么读书，并且Hofferth和Sandberg纳入了很多牢靠的控制变量，而且你确实可以通过读书学到很多。
I’ve long argued that the effects of parenting are overrated. H&S’s results lead to a separate but related result: How kids spend their time is overrated, too. If adults really wanted to raise kids’ test scores, they’d adopt the maxim, “If the kid has a book in his hands, leave him in peace.”
我一向主张，家长的影响被高估了。Hofferth和Sandberg的结果给出了一个不同而又相关的结论：儿童支配时间方式的影响也被高估了。如果成年人真的希望提高孩子的考试分数，他们应该采纳这条箴言：“子执卷，汝勿扰。”
Which, by sheer coincidence, was the maxim young Bryan Caplan vainly begged all the adults in his life to embrace. Reading rules, school drools.
无巧不成书，这正是后生Bryan Caplan徒然规劝天下父母以终身信奉的格言：阅读至上，学校误人。
翻译：史祥莆（@史祥莆）
校对：Marcel ZHANG（@马赫塞勒张）
编辑：辉格@whigzhou