The S-Curve

Welcome to The S-Curve

Now you will be able to receive the latest announcements, product updates, and our insights on the mortgage market in real time.

The name of the blog, the S-Curve, is a reflection of our logo and the central feature of our prepayment model. S-curves are seen in nature in many phenomenon, from population growth to prepayment and default models. Our first S-curve, in the early 1990s, used the arctangent function, then piece-wise linear functions, and evolved over time to be more complex and vary by FICO, loan size and LTV. This evolution encapsulates both the timeless nature of fundamental relationships and constant innovation to describe them better over time.

We hope you find the information useful and we look forward to your feedback.

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Blog - Latest
  • Gritty Renaissance: AD&Co Visits Detroit

    Tom Parrent

    Thoughts

    AD&Co held our annual employee meeting in Detroit, Michigan. In addition to gathering everyone in person to socialize and strategize, we use these annual meetings to learn about different cities, especially with regard to housing market dynamics.

    We chose Detroit because the oft-maligned city is undergoing a significant renaissance, and we wanted to explore the area and learn how housing may have played a role in both Detroit’s decline and rebirth.

    From the early 1900s through the mid-1960s, Detroit was an industrial and innovation powerhouse. Beyond automobiles, the southeastern Michigan area attracted new residents with jobs in everything from heavy industry to machine shops to transportation.

    Detroit has always had a substantial share of single-family houses compared to other industrial hubs, which relied more on high-density multifamily housing. While homeownership rates were generally high, opportunities were not evenly dispersed, as racial redlining led to largely segregated neighborhoods and lower homeownership rates among blacks and ethnic minorities. Although redlining was common in the first half of the 20th century in many large American cities, Michigan set itself apart.  Its Home Rule Act allowed a great deal of self-governance by small cities leading to the creation of dozens of very small towns, all with different public services and both subtle and overt discriminatory policies. The Home Rule Act also allowed large companies to heavily influence local taxation policy and effectively create low tax havens in small towns, thus starving the greater Detroit area of tax revenue.

    Detroit started facing significant troubles in the late 1960s, as the 1967 race riots led to significant white flight. The OPEC embargo in the early 1970’s increased oil prices and opened the door to more fuel-efficient foreign competitors in auto manufacturing. The city’s decline began with significant population loss due to both unemployment and migration to suburban areas, resulting in deterioration of inner-city housing stock and severe underfunding of public services such as police, fire protection and education.

    Long known for its grit and determination, Detroit started to come back in the 1990s and early 2000s as the auto industry recovered. However, much of that progress was lost during the Great Recession due to predatory lending and the second collapse of American automakers. Many large blocks of the inner city were left with only one or two houses standing, and arson for insurance money plagued the housing stock.

    However, Detroit’s revival in the past ten years proved even bigger than all of its setbacks. The Lions, Tigers, Red Wings, and Pistons now all have their venues within easy walking distance of the revitalized downtown business and entertainment district. The city built a new riverfront parkway and renovated parks. Downtown has incredible energy once again, with bustling businesses and residential towers going up, not to mention the burgeoning art scene popping up in multiple locations.

    Laura Grannemann, Executive Director, Rocket Community Fund & Gilbert Family Foundation, gave an overview of the organizations' endeavors in the community. As one of the nation’s largest mortgage lenders, their Detroit Home Repair Fund and Detroit Tax Relief Fund work to head off displacement through preventing tax foreclosure and eviction.

    Detroit still faces many challenges, particularly in those neighborhoods hit hardest by out-migration, foreclosures, and underinvestment in city services. Wealth and influence remain highly concentrated, and the Home Rule Act micro towns remain an impediment to healthy Detroit finances and provision of basic services. Despite this, we found encouraging pockets of home-grown revitalization. Jeanette Pierce, president of City Institute, showed us how hyper-local organizing is bringing growth and renewal without troublesome gentrification and displacement. We met leaders from organizations such as the Southwest Detroit Business Association, Capital Impact Partners, and Live6 Alliance that advocate for fair housing and community engagement. Keeping people in the neighborhoods that multiple generations have called home is a hallmark of these local initiatives. Tactical rezoning has helped overcome some of the obstacles to development presented by Detroit’s traditional focus on detached single-family housing.

    The team also met Ike Blessitt, who personifies Detroit’s gritty reputation. Ike grew up in Hamtramck, one of the Home Rule Act towns completely surrounded by Detroit. As a four-sport high school star athlete, Ike attracted the attention of Detroit Tigers scouts and eventually made it to the major leagues with the 1972 Tigers. Today, even as a 76-year-old double amputee, Ike has continued his 15 years of teaching individuals, aged 6 to 60, how to play baseball. Like the development efforts, Ike keeps it local to help inner-city kids by building a complete baseball training facility in his Detroit backyard. The Ike Blessitt Sports Academy attracts kids from throughout Detroit.

    We came away from Detroit with a real appreciation for the daily challenges its residents overcome through innovation and community organizing. The lively sports and entertainment district will surprise new visitors, but digging deeper into the neighborhoods will show that this renaissance is just getting started.

Blog - Archives

The S-Curve Archives

  • Tom Parrent

    Thoughts

    AD&Co held our annual employee meeting in Detroit, Michigan. In addition to gathering everyone in person to socialize and strategize, we use these annual meetings to learn about different cities, especially with regard to housing market dynamics.

    We chose Detroit because the oft-maligned city is undergoing a significant renaissance, and we wanted to explore the area and learn how housing may have played a role in both Detroit’s decline and rebirth.

  • Niraj Tailor, Hikmet Senay

    Products

    Andrew Davidson & Co., Inc (AD&Co) is pleased to announce the beta release of MARS+, the next generation of Mortgage Analysis & Reporting System (MARS), which has been in use since 2008 for performance reporting of AD&Co models. MARS+ aims to provide enhanced and advanced capabilities and features for mortgage analysis and reporting.

    The new enhancements of MARS+ include:

  • Eknath Belbase, Laura Silberg, Aidan Loftus, Joni Baker, Sam Sutton, Richard Cooperstein

    Events

    Several AD&Co employees attended SFVegas 2025. This post shares their unique perspectives from attending the conference and key takeaways from the sessions.

  • Eknath Belbase

    Thoughts

    We’re excited to announce our latest Quantitative Perspectives providing in-depth insights into current market trends and advanced valuation techniques. This publication offers valuable information for mortgage market participants and those involved in credit risk transfer transactions.

  • Laura Silberg, Andrew Davidson, Eknath Belbase, Alex Levin

    Podcast

    Tune in to Laura Silberg's interview with Andrew Davidson, Eknath Belbase and Alex Levin as they discuss their latest Quantitative Perspectives, our independent commentary series, titled 

  • Andrew Davidson

    Thoughts

    As providers of mortgage models for financial institutions, Andrew Davidson & Co., Inc. (AD&Co) enables clients to validate their use of our models and offers documentation describing the conceptual framework of the models, back-testing results, and sample forecasts under a variety of economic conditions. We also work with analytics providers who have incorporated our models to ensure that the models works as intended.

  • Alex Levin, Andrew Davidson, Eknath Belbase, Mickey Storms, Nathan Salwen

    Thoughts

    We’re excited to announce two new Quantitative Perspectives that provide in-depth insights into current market trends and advanced valuation techniques. These papers offer valuable information for mortgage market participants and those involved in credit risk transfer transactions.

  • Joni Baker

    Events

    Andrew Davidson & Co. Inc. (AD&Co) proudly sponsored the Information Management Network (IMN)’s 10th Annual Mortgage Servicing Rights (MSR) Forum, held November 21 - 22, 2024 at the New York Marriott at Brooklyn Bridge.

  • Michelle Stepien Breier, Alex Levin, Matteo Caracciolo-King

    Podcast

    Tune in to Michelle Stepien Breier's interview with Alex Levin & Matteo Caracciolo-King as they discuss their latest Pipeline article “AD&Co Updates its Home Price Index Model.” The interview highlights key points from the article as they share recent updates to the HPI3 model.

  • Andrew Davidson

    Thoughts

    With the increasing volumes of Synthetic Risk Transfer (SRT) and Credit Risk Transfer (CRT) along with the discussion of BASEL III, we thought it would be useful to re-issue our comment letter to FHFA on the capital treatment of Credit Risk Transfer.