Bill: Choose a cause that’s important to you and get involved. Whether you can donate your money, your time, or your voice, there are thousands of incredible nonprofits that could use your help. I’m a big fan of ONE, but websites like Charity Navigator and GuideStar can help you find other reputable organizations working on the issues that you care about the most. If you’re interested in volunteering, our foundation put together a good list of resources to help connect you to opportunities.

Melinda: Remember that no one is born a change-maker. It’s something you become when you see a problem, then dare to become part of the solution.

If you want to know what that looks like, just look to the young men and women of Marjory Stoneman Douglas High School. In the wake of unfathomable and unacceptable gun violence, these students are insisting that their tragedy will be the last. “We are going to be the kids you read about in textbooks,” student Emma Gonzalez said last week. “We are going to change the law.”

This is how change happens. With bravery, hope, commitment—and the knowledge that progress only comes when we stand up and demand it.

Melinda: It’s not easy to sit with parents who tell you about the children they’ve lost, or to visit a hospital where patients have been abandoned because they’re dying of AIDS. And after nearly two decades in this work, I can tell you that it never gets any easier. But instead of turning away or steeling myself up in these situations, I make a conscious choice to stay as open as I can. Because when someone decides to tell you their story, what they’re really doing is pouring their heart out to you—and I believe it’s my job to listen, and ultimately to pour what I hear back into the foundation. The stories Bill and I hear can be heartbreaking, but they keep us focused. They’re a constant reminder of why we’re in this work. 

Bill: Technology gives us more leisure time by raising productivity. Having things like tractors, dishwashers, and personal computers made it possible to take off weekends, go on vacations, retire earlier, and so on. Artificial intelligence will continue this trend.

I think you’re right to wonder how it will affect our purpose in life. If someday AI lets us make twice as many goods with half as much effort, what will we do with the rest of our time? On one hand, history suggests that having a lot of idle young men can destabilize a society. On the other hand, if we channel people’s energy well, we can harness their talents to become teachers, work with the elderly, and solve other problems.

Melinda: Algorithms are already informing the way doctors treat patients, judges sentence criminals, and banks determine who’s eligible for a loan. AI has the potential to shape those decisions so they’re smarter and fairer for everyone—but only if we can avoid writing racism and sexism into the code, and biasing these systems in a way that will be almost impossible to fix a decade or two from now.

That’s one reason why I’m committed to helping more women and people of color get into tech. I believe we stand a much better chance of getting this technology right—and ensuring it creates a better future for all of us—if we have people of all genders, ethnicities, and backgrounds creating it.

Bill: It’s too early to say. The group of private investors I mentioned in the letter is focusing on five areas. One is grid-scale storage, which could solve the problem that solar and wind energy are not available 24 hours a day, 365 days a year. Another is liquid fuels, which involves using the energy of the sun to create hydrocarbons in a process similar to photosynthesis. Geothermal is a third focus area for us. There are many more possibilities, some of which we’re investing in. The key is that the world needs to be aggressively pursuing lots of ideas, because no one really knows yet which ones will lead to the big energy breakthroughs we need.

Melinda: Looking at the big picture, the answer is a resounding yes. Worldwide, the number of women who have access to modern contraceptives has never been higher. The number of women dying in childbirth has fallen by nearly half in just a single generation. Access to education, jobs, and financial services is becoming more equal every year—a fact you can not only see in the data, but hear in a mother’s voice when she tells you she believes her daughter will live a better life than she did.

Of course, the rapid progress we’ve seen makes the remaining barriers to gender equality even starker. I’m heartbroken when I travel overseas and meet women who still do not have the right to own land or the ability to plan and space their pregnancies. Here in the U.S., I’m outraged to see the same kinds of bias and discrimination I experienced 30 years ago still locking so many women out of leadership positions and career paths. But at the end of the day, I’m optimistic about what the future holds. In 2018, women are speaking out louder than ever. Our voices are being heard. And with the right support, I have no doubt that women’s movements will continue to drive progress toward a world that’s more equitable and more prosperous for everyone.  

Bill: I’m optimistic that we’ll see a significant breakthrough within the next 10 to 20 years. Our understanding of how the brain ages is advancing a great deal, and that’s fueling a lot of promising research in new areas. Most of the drug trials so far have focused on two specific pathways to treatment (amyloid and tau). I hope those approaches succeed, but I’m excited that scientists are also beginning to explore less mainstream targets. A more diverse drug pipeline will increase our odds of discovering a breakthrough.

Melinda: Through years of doing this work, I’ve seen time and again that when women have the tools to do what’s right for themselves and their families, they transform societies.

At the foundation, most of our work is focused on improving global health and helping people lift themselves out of poverty. Empowered women are essential to driving those outcomes, which is why we invest in family planning services, maternal health care, women’s movements, and more.

In 2015, I created an investment and incubation company called Pivotal Ventures. Some of the issues we’re looking at include expanding access to paid family and medical leave, helping more women join and thrive in the tech industry, and closing the enormous gender gap in who’s giving and receiving venture capital. Pivotal’s model is based on partnership. We’re working with a wide range of individuals and organizations with a shared vision for social progress and commitment to improving lives.

Bill: Health equity. I want every person—no matter where you live or what your income level is—to have the same opportunity to grow up and thrive. There are plenty of reasons to think this is achievable, especially when you look at the dramatic improvements the world has made already. The number of children who die before their 5th birthday has been cut in half since 1990, and 86 percent of kids around the world receive basic vaccinations. If we keep making progress, I’m hopeful we will one day live in a world where a child born in sub-Saharan Africa has the same odds of surviving to adulthood as a child born in Europe or the United States.